Currently for 1 statistic and skill I'm wondering if I do some modification leveling up, if I'd be wasting resources. I'm at 5 luck and have Finesse (perk) and am wondering if I increase luck if it won't make a difference for critical hit chance since 6 base + 5 finesse > 10 and AFAIK statistic is capped at 10. I'm at 100 stealth and am considering getting Broad Daylight but since 100 + any # > 100 so there will be nothing to offset as AFAIK skills are capped at 100.
Skills are capped at 100, so anything that goes over that is wasted as far as I know. But Broad Daylight's wording might imply something different. The light from the Pipboy seems to affect stealth in a way that isnt tied to your sneak skill. In other words, I think the light makes it easier for you to be detected, but its not by giving you a sneak penalty. You should probably save right before a level up and experiment with it to see if it makes a big enough difference for you to get it. I personally prefer to use Friend of the Night or Cateye (with some mods to adjust the effect) to be able to see in the dark.
Luck is capped at 10, but base crit chance (which is affected by crit multipliers) is not, so you can take advantage of perks/gear that add to your base crit chance and weapons with high crit multipliers to in theory have 100% chance to crit on every attack, or at least thats how I understand it.
The main reason I use light is to spot traps (which is not that big of a problem until I get to enemies, then I have to choose to do ranged or do my good 'ol melee but taking a chance to trigger a trap). I tried the varmint night vision (modded), Riot Gear Helmet, then Cateye, they're considerably better than regular unlit, but not as good as light, especially since I've been using SmoothLight - Pip-Boy light enhancer. I'm not good at testing, but I'll do so if I have to; hopefully someone that is sure about it can share it with us.