Is "tools" another word for "boobs and butts"?
Anyway, welcome! I'm new to the series too, been playing for just about 1.5 months, so my advice is not that of an expert.
As for comfort, I presume that'd be personal preference, yeah? How you like their fighting style, inputs, etc. For instance, I like dual-maining and had it narrowed down to Ramlethal, Bedman, Haehyun, and Jack-O'. I narrowed down Jack-O' (as much as I loved her) b/c her sweep input is different than everyone elses, and I like consistency between the characters I play. I picked Ramlethal b/c I liked her combination attacks (something I'm used to from my time in NRS games). Bedman vs Haehyun just came down to flavor preference. I dislike DP inputs, so I was a bit reluctant to pick Haehyun, but after watching some vids, I learned you can be a good Haehyun player w/o using her DP. But yeah, it came dow to a teenage girl controlling a buff old-man mech vs a teenage boy who's asleep on a mechanical, weaponized bed. Both are bizarre and interesting concepts lol, but I just liked Haehyun as a character just a bit more.
Imo, Jack-O' and Ram seem pretty versatile, Baiken seems decently versatile. I-No seems to have good mixups. They are all fairly weak on defense per http://www.dustloop.com/wiki/index.php?title=GGXRD-R2/System_Data, but I'd say I-No and Baiken seem to be the worst, although Baiken has really good Guts. None of those characters have charge inputs, afaik. I've read that's just Leo, Axl, Pot, Venom, and May.
As for representation, i'm a PST player and in the PST and newbie rooms, I do see a lot of Ramlethal, some Baiken, a little bit of Jack-O', but rarely I-No.
Anyway, I'd suggest looking at all of their individual pages from http://www.dustloop.com/wiki/index.php?title=Guilty_Gear_Xrd_REV_2 to maybe get a better idea or more information for what you're looking for.