Considering the fact that you get 5 skill points (according to guide) what's the most effective stat distribution without taking the future into consideration?
you get 5 skill points
It's 9 skill points.
STR 7, AGI 7, END 4 is the base. STR must be 7+ otherwise your Damage is too low to get meaningfull progress. AGI should be 6+.
INT and CHA are practically useless against the first bosses. So STR and AGI are the only important stats to savescum skullface. If Skullface does miss his attack you quicksave. IF Skullface hits you, you quick reload until he misses. Every few minutes you should save normally, it's ez to loose track. ROLLBACK does not work. Sometime Eyvind lands a huge critical hit with insane damage (45+) In these cases you may want to save your progress even if the enemy takes a few of your life points.
without taking the future into consideration?
Starting with high STR is actually very benefical. With STR 8 you can win the armwrestling agains Harken, and later a wrestlingmatch against Tomahawk. Every stat with 7+ is helpful in the underground City to farm beorc. Don't forget to raise END and you got a fine "warrior build" for your Eyvind.