1) Is speed investment more important than constitution and perception for having enough ap points each turn ( i feel starved atm)?
Perception determines your APS during the very first turn. Speed determines your recovery APs during subsequent turns. Constitution determines the maximum APs during one turn you can have. So, if your speed allows for 12 recovery APs and your constitution limits your APs to 10, then 10 APs is what you get. The best solution would be to mouse over APs in the character inventory screen and look on how much recovery APs and maximum APs you have. However, my guess would be that at the beginning of the game your maximum limit of APs due to constitution is not reached and it is indeed speed which you should improve.
2) Are str/dex more important than bows/two arms/ etc for damage?
Str/dex determine your hit chances for strength and dex based weapons. The damage is increased by the weapons and by the skills (two-handed/one-handed/bows or something like that)
3) More skills into school of magic increase magic damage?
No, skills into school of magic increase the number of spells you can learn of this particular school and reduce the AP costs for higher-level spells. Pump intelligence in order to increase damage output.