Unless you are leading PUG raids, you do not need any kind of "score" addon for checking other players' gear; the LFG/LFR content is nowhere near fine-tuned enough for gear to matter beyond whether the system lets you queue for it, and in a guild, you should trust your players to know what stats their class uses and equip/enchant/gem/reforge appropriately.
Even if you are forming a PUG raid out of trade chat (does that even happen these days?) the average item level that the game provides nowadays is really all you need to know... addons like
Equipped Average Item Level Tooltip (could that name be any longer?) can add it to players' tooltips, and inspect addons like
Examiner show you that (and more) when you inspect someone.
For cooldowns and DoT timers you might check out
Raven or
ForteXorcist. Both can do DoT timer bars and "timeline" style cooldown bars. Raven can also do regular buffs/debuffs, and I know its author is very active in answering questions. Forte has more specialized features for warlocks, but does work for all classes.
If you're looking for a standalone cooldown addon, I second Kendian's recommendation for
CoolLine.
I don't personally use any DoT timer bars since my unit frames have custom aura filtering, but some popular standalone ones include
nugRunning,
Ellipsis, and
NeedToKnow, and you can find lots more in the
Buff, Debuff, Spell category here on WoWI.
For the minimap, there are
tons to choose from; just browse the
map addons category and find one you like.