Odd that you can level up for example "Cool" attribute to a higher level from the main screen. But if you click into it and upgrade attributes of that category, it doesn't bring your overall attribute level up?
hmm, what do you mean? cool works just like all the other attributes for me (reflex, body, technical, intelligence). you can level it up with attribute point (Rarer), thus increasing the stats it is tied to, as well as unlocking the perks within its linked perk branches (so, both stealth and cold blood). perk points (easier to obtain) can be used to level up those perks as they are unlocked by leveling up the main attribute.
perk points only bring up the level of each skill/perk within their own tree, but the attribute points that you get (1 for each level, as well as the 1 perk point), can only level up the attribute level, and it's only the attribute level that will unlock the levels within the perk tree (so, at level 11 Cool, you can access all of the level 11 perks within stealth and Cold Blood)
HOWEVER! each perk tree does have a separate level 20 PERK skill. So, say, within COld Blood, there is 1 level 20 ATTRIBUTE perk (needs 20 into Cool to unlock it), and one level 20 PERK skill of that tree (so, 20 levels of that PERK, so 20 into Cold Blood, that can only be leveled up by using the perks within that tree--Cold Blood is hard to figure out, because a lot of it isn't "Active" skills, like the reflex skills, handguns and blade, that are basically "shoot handgun or kill with sword/knife" to level up those perks. You've noticed how you level up those specific perks just by doing stuff--hacking, shooting, etc. Those levels will often award additional perk points on top of buffs to that activity (like more crits for handguns). Anyway, that system works for the entire attribute/perk mechanic as far as I have noticed. Haven't seen "cool" be handled differently than the others, or in a different menu.
as for hacking...yeah, it's confusing. The quick hacks and the "mod hacks" --which I think are the mods you can equip and unequip to your cyberdeck, and change your skills, are different. I actually haven't once upgraded my cyberdeck, so I've neither tested it nor practice it, but I think it works this way:
cyberdecks use skills in 2 different ways, all of them (that I have seen, anyway)
--there are slots in each one, depending on quality of cyberdeck (say 2 slots vs, maybe up to 5?), that you can switch out skills from items that you acquire.
--there are inherent skills attached to each cyberdeck--you see these as icons in the cyberdeck's item card, under "quickhacks, I think," These are permanent to that cyberdeck. It sucks, because you can't hover over the icons and get a description. I'm not sure if the crafting/upgrading function will actually replace those or not, though. I believe it can increase the slots, though.
a lot of the skills are quickhacks that you use directly on targets while scanning, where as a lot of the mods that you can slot in and out are more passive, I think (say when you jack in to steal credits, it influences your success in those? I'm not really sure, tbh...I know tehre are perks that do this, but again, I haven't spent enough time with that to find a build that makes me want to put together a hacking sort of build.)
scanning and looking at all the cameras and machines and trying to control that stuff, as well as mobs...just isn't working for me right now. I dunno, cameras seem to just cut back on, even if I know that I haven't been spotted. A lot of your hacks are blocked by npcs and items, and there is no clear reason why. ram use needed to perform the same tasks varies widely depending on where you are, and I don't get it (enemy level/inherent stats? item level--a lot of these don't have levels, vs those doors that you need more body or tech points to open...it's just "device that blocks your scanning for some reason")