I think the game would feel a lot better and more balanced if the strength requirements went up as you upgrade weapons and armor.
Before the item degradation patch, the game was easily beaten if you found a non-cursed tier 4 or 5 weapon early and upgraded it, equipping it (with the lower Str requirement), and one-shooting most baddies through floor 20 while you stock heal pots and continue to upgrade weapon/armor as you go. Degradation adds some problems to that plan, but if upgrading caused the requirements to go up rather than down, you'd prevent players from getting massively overpowered weapons/armor for their level, and introduce an effective weapon level cap based on strength rather than scroll of upgrade rarity. Not being so limited on scrolls of upgrade would force some interesting decisions about weapon upgrades and usage, as it might make sense to upgrade a low tier weapon while you wait for strength to allow for the higher tier weapon. Also, a tier 1 +4 weapon would be more effective than a tier 3 +0 weapon with the same Str requirement. Finally, it logically makes more sense that bigger weapons that hit harder require more strength to use.
That's my 2 cents. I love this game, though! Great work, developer!