mmm. this is more in the realm of one of my favorite classes... and yet... more tricky at the same time. lol. rogues, while perfectly capable of soloing with a good build and skill, can be tricky to solo with as a newer player. that being said...i have an idea! but first, a few points
part of the reason rogues might have trouble soloing as opposed to grouping is sneak attack. traditionally rogues were all about the sneak attack. a pure rogue assassin with all associated sneak attack bonuses could still be doing upwards of 100 damage per hit at 20th with daggers and no power attack...as long as the mob was not aggroed on him/her... because of sneak attack
acrobats are much more 'in your face kick your butt', so while their sneak attack damage is still decent (but not as high as an assassin's) their primary DPS is (typically) higher and more reliable.
assassin can be fun as a 'sneak in... kill the target... sneak out' kind of self challenge build, and if you have ways to make mobs blind... you can seriously f up a dungeon in quick order.
for any type of rogue... bluff is your friend. bluff pulling* is very powerful. yeah, it's slow... but fighting one mob at a time at your leisure = good... dying in a massive mob of mobs = bad
another reason a rogue, at low levels, might have trouble soloing... is lack of inherent healing. it's not as much an issue at later levels... rogues get UMD as a class skill, so heal scrolls! yay! but it can be difficult in the low to mid levels. (this can be overcome with various means that have been discussed at great length in the forums... potions, wands, hires, class splashes, half elf, etc.)
all that being said... my idea is... dragonmarked halfling. XD self heals built in!
for staff build, i would say definitely add monk in. at least 6 levels. ninja spy shadow fade is teh win. XD
i JUST posted an elf stick build above... and if i dig i'm sure i can find the build for my rogue's second life (rogue/monk assassin) which was a ton of fun... not as direct examples of what to build (they would at the very least need to be tweaked for a 28 point build) but as an idea of what might be good.
let me think on it a bit more... or harass me in game... and we can sort thing out.
also, if you want to get an idea of some of the awesome things rogues *can* do... click on the red R.O.G.U.E. link in my sig. ^_^ maybe someday soon i'll be adding some of YOUR accomplishments!
*bluff pulling: the art whereby you sneak to just barely within bluff range, target a single mob, and bluff it. it will come running to you, leaving his buddies behind and confused. slow, but easy. each fight is one-on-one.