Like I said in a previous post. You could alternate your advancement of umd and open locks. So one level bump them both the next just bump umd and add a point to hide and move silent and the next bump open locks not umd and add a point each to hide an move silently. If you do this a couple of times your umd will still be high enough with the golden cartouche and a hero pot to equipstuff and your open locks will be good enough for 99.9% of the locks out there.
If you don't mind waiting until level 10 you get evasion at level 9 ranger. So going 2 levels of rogue is not really needed. Also with a 12 int you won't be able to keep all skills up.