They are there to replace living things without resorting to necrophil...mancy. Protecting your tomb or hidden treasury for 1000 years is easier with mechanical and magical traps, and not as expensieve as golems. Minimum of 10 so that at least one of them finishes the intruders off.
Well its a load of hp attack and damage bonus, so just add another +1 for it. No need to make things overly complicated. If it goes wrong then hey, more xp for the players. I doubt they complain.
What is the party composition and levels?
It grants way more, extra skill proficiencies, possibly better stats, more attack, more damage. The main downside is supposedly the heinously low ac, whcih should balance it downwards at lesst slightly.
Oh i am fine.
You should look at my horse. It is amazing. If you lick it, it tastes just like raisins. It can ride all over universe and other places too.
I havent dm'ed yet but maybe the extra abilities grant to a cr of that a 6th level druid and +1 added due to aggressive and gruumsh fury abilities. Not sure how much that would add up to
Doubtful. You may increase the danger cr, but xp based should be the same. Killing an npc druid shouldnt yeald any more xp than killing a fighter npc of same level.