As I thought. You have an extremely permissive DM. Yet you think it’s the spell that makes things unbalanced.
Oh yay. I always love these conversations, they are always so fruitful. Please, bless us with your wisdom.
Firstly the easy one. Unseen servant is mindless and you can’t command it to search a room. That requires intelligence and it’s limited to simple tasks. What stat did your DM make your mindless unseen servant test against for a search test? Lift a key of a peg you can see ok. Search a room, nah! Even ignoring that you took 10 minutes to stand at an open window of the house you were breaking into to cast unseen servant to make it search a room that your permissive DM was generous to let you do… rather than let the rogue take a round to pick the lock? You think the problem is with the spell?
Ah, of course! The servant is mindless so it can't do something like find a key. That would be silly. Why it is limited to tasks like "The servant can perform simple tasks that a human servant could do, such as fetching things, cleaning, mending, folding clothes, lighting fires, serving food, and pouring wine."
Huh, that's weird. You know, the very first thing on the list is fetching something. Now, I don't know about you, but since the Unseen Servant can perform simple tasks that a human can... well, if I asked a human to fetch the bottle of 950's Argonian Wine... I'd expect them to be able to do it. Even if the wine bottle was not in perfectly clear line of sight. In fact, the servant might... have to search for the wine. It may have to open a cabinet. And yet the spell tells us it is perfectly capable of the task. Ah, but that is but a single example right. It isn't like there is a far more complex task on this list, right? Such as... mending?
Now, I don't know if you have ever mended clothes, but it is actually an incredibly complex task. First you have to grab the correct article of clothing, it may even be multiples, but we'll start one at a time. Then you need to get the proper needle, the proper color thread, matching buttons... if the servant lacked the intelligence to look for something... how is it finding all of these things and THEN properly utilizing them to actually effectively mend the clothes?
See, you mistake is you are misinterpreting what "mindless" means. See, mindless is usually utilized to describe someone who is not thinking about something or concerned with something. A mindless task is a task so easy you can do it without considering the task. It is something that... could be done by a machine. And thus we get into what is meant by the spell. Unlike a familiar, or a conjured creauture, the force created by unseen servant lacks a mind, it lacks a will. It is an automaton. That doesn't mean that it cannot successful complete a complex task, that means it has no opinions, no thoughts, it simply does what you say. It cannot observe and report.
Now, maybe the DM did have the key on a hook. I don't know. We didn't have to roll anything, and we didn't have to see the key ourselves. The servant was given a task, and it completed it. That's what it does.
Secondly control water. Anything much bigger than a big 15 foot row boat isn’t affected by the flood effect at all. The ship goes up the wave and over it and isn’t moved. The spell specifically says only huge or smaller boats are affected which in D&D terms is a large rowboat. That 70 ft ship you mentioned is gargantuan. So not moved. Even if it did move (which they don’t) why would the ships colliding destroy the ships? Ships might bump particularly when travelling in the same direction why on earth would you expect that to do catastrophic hull damage? Even a full blown intentional ram at full speed with a ship designed for ramming in 5e wouldn’t destroy a ship with 300 hp. You got that effect from a wave? It also wouldn’t be affected by the whirlpool… firstly the ship is bigger than the whirlpool which is 50ft wide at the top. Sure it does bludgeoning damage to objects. But the ship has a damage soak of 15 so unless you need to get a really really good roll on 2d6 to damage that ship. What is it about the spell that makes you assume the effect would drag a gargantuan ship underwater and sink it? It doesn’t even do that to medium sized people let alone immense objects, creatures just spin around the vortex they don’t even drown. Even the enormous 500 foot whirlpool in Pirates of the Caribbean didnt why would you think your 50 ft whirlpool would too? In this example you and the DM just got the spell wrong.
Why would two boats being forced to move 100 ft in six seconds, crashing into each other damage them? That isn't a bump. And it didn't need to immediately destroy the ship, just cause it to start sinking. Which hull damage can absolutely do.
But since you are so obsessed with the size, I dug through our old files. The game was only two years ago, so I still have the map. And it turns out, I was wrong about a few things.
It was only the whirpool, I didn't use the flood. And they were 20 ft long long boats. So, they were small enough. Also, the whirlpool does 2d8 damage. Kind of weird you want to rant about my DM getting the rules wrong when you are also getting them wrong.
But let's take a moment here, before I get to you cracking up. How do the boat's escape the vortex? They need to make a strength athletics check, and since they are caught, that would be with disadvantage. So that would be a check based on.. the rowers, right? So, once the boats were caught, they were stuck and taking damage. Even if it didn't happen in a single round... who cares?
Finally, Wall of Fire cracks me up. Wall of Fire doesn’t damage objects in the first instance. It damages creatures. It literally says that in the spell. So the ship isn’t set on fire at all. Secondly it is a perfect circle or a line - you can’t make it boat shaped. So unless your ship was circular there would have been a safe space at the front or the back. But let’s say the crew jumped over board - they would have been burnig
If I’m the radius so it makes sense. Why didn’t they just swim back to the absolutely-not-on-fire ship? Of course it’s not possible to cast wall of Fire on the deck of a ship either way because it has to be a solid surface. Ships move… that’s literally what they’re intended to do. So that ships deck isn’t there a second later? Or do you think wall of Fire can fly now? First time I’ve ever seen someone advocate for moving walls of fire.
Yep, I totally see that docked ship moving and there is clearly spaces at the ends where they could safely stand.
By the way, did you know that planet's spin? They actually aren't stationary. Guess that means wall of fire can't be cast on the planet. Or, it turns out, that a ship's deck is a solid surface by literally any definition of the terms, and the point is you can't have a wall of fire bridge a gap.
And you know, a massive wall of fire catching flammable things on fire... isn't exactly a stretch. Especially since the majority of fire spells make mention of it. And things like Flame Storm specifically allow for things to not be caught on fire. Unclear rules or a DM bending over backwards to lavish their player with undue power? Frankly, you will say the second even if I could find the transcripts of the exact interaction.
Just like you claimed you one shotted a 14th level rogue with Whirlwind despite the fact that it would only deal 5d6 damage to the rogue - none on a Dex save! (they have Evasion) and the damage is only dealt once, not every turn.
Different DM.
I think maybe if I was your DM you would have a more balanced view of magic. I don’t have a problem with players making mistakes with spells. I also don’t have a problem with generous DMs. I do have a problem with folks claim it’s the systems fault.
I never claimed any of this was the systems fault. I claimed that having these options is more powerful than not having them. But I'm sure you'll continue to berate me because my DM didn't specifically cater to your exact interpretation of the rules and therefore everything I did was invalid and therefore the fact that the barbarian in the group was just standing around waiting for an enemy to get closer and had no access to AOE's at all is totally my DM's fault for being too nice and not the fact that the system gives spellcasters far more options than it gives martials.