(1) Boosting the surviving kobolds' power "just because" really sits wrong with me.
What level should NPC's be? Answer - whatever level the DM needs them to be to fairly challenge the party. NPC's are not subject to the same rules as PC's. The PC's created this particular pair of villains even if they don't know it yet. That will make their defeat all the more enjoyable when the party does finally accomplish it.
If two kobold skirmishers want to try and mess with a decent sized settlement, that is fine. They won't get far.
Why? Because the world can take care of itself and the world doesn't really need heroes? Bollocks. The PC's are heroes, a cut above Joe Farmer and John Dirt that run this township. They aren't able to deal with kobold minions effectively, let alone two that by inexplicable twist of fate are a cut above the average kobold (just as the party members are a cut above the average members of their race).
If you don't give the kobold's vastly level inappropriate abilities they will get tracked down and summarily executed.
Must be a boring campaign you play or run, where the party doesn't *need* to handle anything because the NPC's can handle themselves and the messes the players create.
*Even* if they somehow manage to survive for a few days and the party starts a trek, tracking groups through the wilderness over long distances without getting noticed is *hard*. Forget about setting traps.
Who said they won't be noticed? And even if they are, can the party keep up and track them down? I'll leave that to the dice.
(2) Congratulations on reinforcing the lesson of "kill everyone", including the "good" humans. As a member of the party, if the town was going to (a) be incompetent enough and (b) dickish enough to toss me out I might well opt to sack the place myself.
The party could certainly succeed at that. Osmon is small and has no particularly notable NPC's other than the Duke and his men. If they do word will spread - eventually they'll run into something that they can't handle and either be killed by it or hide from it.
Again, this is a superstitious collection of lakefolk. Until the party arrived they'd never seen a dragonborn - they've only rarely seen elves and eldarin. They've never seen a tiefling but halflings are common enough. They don't owe the party anything and if they think that tossing the group outside of the walls of the town will protect their children, they will.
If they can't protect themselves from a few kobolds, they won't be able to hold off the party (see point 1), after all; and being that weak, it isn't like the town will be there next year, anyways. Might as well salvage some supplies for the trek from the doomed settlement, and deny the enemy the opportunity to do the same. Note that once you see the other town destroyed, this argument becomes even stronger. Without any other settlements anywhere nearby, that town is dead.
Right... As I noted earlier - your campaigns must be extremely boring since the world has no need of heroes and everything can take care of itself.
One thing that you want to be careful of is making the kobolds metagame. As a DM it can be easy to make all NPC plans work out perfectly because of course you know all the factors and every detail of the world. If they want to foul the water supply, it automatically works. If they want to lay traps ahead, it automatically works. There's no plans that they can come up with that the DM will reject. The PCs don't have a direct connection to your imaginion and hence are at a disadvantage in this kind of contest. For example, why do the Kobolds automatically know that this tactic they're using will get the villigers to throw the PCs out rather than hiring the PCs again to protect them against the renewed Kobold? They seem like they're a mechanism to "punish" the PCs for no good reason.
Again refer to my first point - NPC's are not subject to the same rules as PC's - they exist to challenge the party and to make the story interesting. The town throwing the group out is perfectly plausible - because of the dragonborn in their number it took the group a long time to build up enough trust in the group to even let this strange creature through the gates. If children start showing up dead that trust is going to break.
Long term the way this gets offset is you let NPC's do things wrong - sometimes disasterously wrong. I've had NPC groups stumble into PC ambushes exactly like the players planned out before. I don't spend too much time worrying about the flaws in their plan or how the NPC's might weasle out of the attack.
Secondly, I'm wondering why you're "shocked" over the behavior of your PCs in killing the women and children. Putting aside whether or not this was the right course of action, it only occured because you put those kobold women and children there. If you didn't want the PCs to kill them, why include them at all? And why make such a big issue out of it, it's not like the kobolds make a distiction between non-combatents as the baby incidient shows. They'd be upset that the PCs killed off their tribe but not any more or less upset that they killed the hatchlings.
The reason they were there is because a lair is a home. Kobolds don't come out of monster spawning pots in my world like say, in Gauntlet. And no, kobolds don't make a distinction between combatants and non-combatants. That's part of the reason they are *evil*. By failing to make that distinction the party acted in an evil manner. I don't use the alignment system itself to deal with questions of good or evil, but those questions arise all the same.
I feel your pain of having to deal with players though, sometimes they can be quite annoying and there's often a great urge to smack them down if only to see them not get their own way for once.
I'm not annoyed at them though. This should be fun to play out - they've inadvertedly created a couple of memorable NPC's to throw at them, and I'm going to enjoy doing just that.
It's called realism (I assume). Where else would the women and children be, if not at the lair? Just because something's there doesn't mean it's automatically meant to be killed, even if it is small and scaly. And it's entirely possible that they were there specifically to see if the PC's would kill them or not.
They were there because they are supposed to be there. How the party dealt with them is a moral quandry.
Yeah. It's a good opportunity for a skill challenge, or a bunch of skill checks.
That it is. What I presented above is a draft of what will occur. It isn't set in stone. I've been DM'ing a long time now and I know that getting attached to one plotline is how you annoy and railroad players. What I've sketched out is what the kobolds intend. Will they succeed? If the **players** do nothing, yes. The onus is on the PC's to stop them. The duty of the DM is to make sure they have a reasonable chance of succeeding, and if they fail that the consquence of failure isn't so disasterous that everyone's fun is ruined.
Yeah, changing the Skirmishers to full up Rangers doesn't sit well with me either. That says to me that you are 'punishing' the players because they did something unexpected.
Again, what level should NPC's be? Whatever level the DM needs them to be for the role they are to fulfill.
Also, what, there's a road from the village to the town/city, but that's it? No other road connecting the town/city to anything else? Yeah, right. Or, worse yet, there aren't any roads (or well travelled trails) at all.
Osmon is on the mouth of the river Ciondras as it changes from Lake Mystal to Lake Telcasi. As recently as 300 years ago there where numerous villages like it all along the shores of the rivers and lakes. That was before the beginning of the 5th Orgstagal war.
The whole region, Losineris, is pretty much devoid of roads because the quickest way to get anywhere important is by boat. Whatever lies inland has become lost to all but the wisest of sages.
Agreed.
Unless there are news of two kobold causing trouble in the area (getting exp that way) or
dead adventurer bodies (that they ganked):
Kobolds shouldn't "level" up into Rangers.
NPC's don't ever level up though. The most lasting damage 3e has done to the D&D game was instilling this notion that NPC's somehow are obligated to be handled like PC's. That simply isn't the case.