So yeah, i am lamenting how worthless STR/INT are for determining the effectiveness of your offensive capabilities in reasonable gameplay. I think the rest have at least a tangental effect, but nothing about the stats makes you deal more (or take less?) damage. You just need to meet class reqs for the classes you want, and then slap some powerful equipment on.
In my opinion, I think it would be better if they make higher tier but heavier equipment for each classes which exceeds their normally achievable weight limit.
In this way, they can make STR as a factor for donning better equipment by increasing the maximum weight limit.
Furthermore, they divide the classes into three general groups, the Tanks, the DPs, and the Support.
For each of the groups, their maximum weight limit will go as follows: the Tanks max.weight is 80 + 180% STR, the DPs max.weight is 50 + 150% STR, and the Support classes max.weight is 30 + 130% of STR.
For INT, they could make it to improve the effectiveness of some item skills and increases the maximum charges of classes spells.
For instances, the item Mage Masher special Healing skills will have approx. 30 base.power +1.5 point for every INT points the wielder possess (subjected to 30% variance).
With 20 INT, you can break the Mage Masher for a 42 ~ 60 healing effect.
For maximum spell counts, Tier-1 Spell can grow to a maximum of 2.8 + INT/1.8, Tier-2 can cap at 3 +INT/2, Tier-3 cap at 3.2 + INT/2.4, Tier-4 cap at 3.4 + INT/3, Tier-5 cap at 3.6 + INT/3.8, Tier-6 cap at 3.8 + INT/4.8, Tier-7 cap at 4 + INT/6, Tier-8 cap at 4.2 + INT/7.4, and Tier-9 cap at 4.4 + INT/9.
So if you have 20 INT, Tier-1 can max at 13 (supposedly 13.9, but fractions will not be rounded off. Any decimal places will be count as zero, for it is insufficient of a whole number), Tier-2 cap at 13, Tier-3 cap at 11,... Tier-7 cap at 7, Tier-8 cap at 6, and Tier-9 cap at 6.
On another note, the chance for instance death should varied between Thief, Spellblades, and Assassin.
Like Thief and Spellblades will get Death Lv.1 (with 24% of instant-kill) at the earliest of Lv.8, and Spellblades can get Death Lv.2 (increasing chances from 24% to 42%) at the earliest of Lv.18.
Whereas Assassin start with Death Lv.1 at the get go, and increases to Lv.2 at the earliest of Lv.8, then Death Lv.3 (improving chances from 42% to 60%) at the earliest of Lv.18.
Most importantly, the girls need to have % resist to instant-death, so that they don't get one-shot kill by the MC once he got charmed by the Elder Succubus while under any professions with instant-death attack.