Hey Ikor, I have probably come too late into this and it seems that Immora has planted some excellent suggestions. In any case, I want to throw in my two coppers in any case because I love unconventional characters.
I noticed this Rogue doesn't have any ranks in Use Magical Device. To me, this is a shame because it is quite useful in a more unconventional sense. With a few ranks, there is nothing stopping Rose Hawksburrow pilfering the Wizard's Wand of Fireballs and letting rip. If a Holy Avenger is placed as treasure, this can make for some good roleplaying and gaming moments for Rose as well, especially because of the unwanted favours from the Church of St Cuthbert (hey, that elf is not the messiah!). Even better because mechanics-wise, it really doesn't have any untowards effects; it simply becomes a +2 cold iron longsword if Rose doesn't make the check.
Another skills of incredible use in combat is Bluff. Feinting in Combat is a great way to deny a Rogue's opponent his Dex bonus and open him up to all sorts of sneak attack-ery, which go hand in hand with the next part:
I would suggest looking at the Complete Scoundrel (if you'll allow the book); within are a number of 'Ambush Feats' that allow replacement of sneak attack damage for a number of different effects, such as, concussion, deafening, confusion, speech hinderance, delaying sneak attack damage are some good examples.
There are also a section on things such as 'Skill Tricks', which may augment skills already taken --at a small price. 'Spot the Weak Point' is a good example of using the Spot skill in combat (allowing the Rogue's next attack to be considered a touch attack). There are quite a number of skills and feats in there, so I would advise flicking through it for some ideas.
To me, Rogues are opportunists to the last; they sneak a look at the wizard's magical items, the Fighters weapons, the cleric's relics. They look for their opening and they capitalise it mercilessly. Hope this helps :)