I've come across different kinds of mobs in SL.

Some that appear out of the ground (bugs, small alien dog things).
Some that just seem to be 'extras', no XP, no kill count, doesn't reduce Bad Guys in the map, no loot.
Named mobs, like mini-bosses but don't seem to be anything more than named and a bit tougher.

I'm a bit confused. Should I even bother solo-ing these Named mobs? I've never gotten anything from them (loot). I think they give XP, but it shouldn't be any different than a normal mob XP, I think.

These 'extras' are really just extras right? Nothing to be gained?

I'm also confused to the mobs that pop out, do they raise the map mob count hence killing them gives the same number of mobs left?

I've just been playing more solo, especially if I just have a few minutes to spare (Guardian runs take too long), and I've come across these things. If I can get any help, it'll really help me solo more efficiently.

Thanks!