As far as I know, from Fallout games, your stats don't go over 10, but I wonder if it's the same in Lionheart?

For example, if you start with 10 intelligence and gain two intelligence perks, at the start of the game, does your intelligence and skill points per lvl go up accordingly, to 12?

Thanks in advance.

Yes.

Elf Archer 45lvl:
https://steamcommunity.com/sharedfiles/filedetails/?id=891839594
PE 18
IN 14
AG 12
LK 11

Can someone tell me how that char has +1 from Gifted, +1 from Gain Perception and +1 from Superior Senses after starting with 9 initial PER? Serpent's Bile / Ale lowers PER by 1 so he should have been able to get either Gain Perception OR Superior Senses, not both. I was aiming for this build as well but the lack of info on Superior Senses ( <10 PER requirement ) caused my build to fail mid-way. I can't take Gain PER after getting Superior Senses.
Is there any way to reduce perception by 2?

Goblin Khan can debuff PE even by 3 (3 times by -1). In addition to that you can use alcohol.

Wow, didn't know that. Just watched a video on youtube and he indeed lowered it (among other stats). I guess I always killed him too quickly before he could inflict that debuff (powder keg)..
So the correct sequence should be
Start the game with 10 PER,
Drink ale and get Gain Perception at lvl 11+
Get debuffed by goblin khan and quickly get Superior senses at lvl 14+
Get other perks n stuff.
Damn, son :)
Time to start again.

Thanks for the info