Yes.. Kind of. It's increased as you defeat bosses. You will start getting raids on your bases.

No quite the contraey stick with it and as you gain skills and build up your SS life it gets a lot easier.

Well my comment relates to ai hunters off.

no,the difficulty only increases if one defeated a boss
take your time and prepare after each new boss new creatures will appear
(stronger creatures will eventually attack your base)

Thats good, makes life better :) Thanks all

I think there are a couple of small things. But nothing you would really notice and wouldn't naturally progress past with just a bow and shield.