One thing you might want to keep with Pathfinder rules is that BAB is tied to hit dice.
A D10 hit dice means full BAB, for this 3/4 BAB you might consider D8 hit die.
Also seems a bit powerful. Are you getting 9th level spells, full sneak attack progression, and ranger combat feats?
Seems a bit beyond what you'd expect from a single class, but I'm not sure how I'd balance it.
As a GM I would never allow something like this. You are cherry picking the best abilities of multiple classes. Limiting your schools to two is not that much a of limitation sense you are probably picking the schools. Only wearing light armor is not much of a limitation for a DEX based class. This class would be stronger than many gestalt combinations. Combining sneak attack with a full caster is over the top.
Alright, I have some ideas that might be able to help you with this idea, and help it make it a bit more balanced. I don't really have any experience with building classes, and there will probably be gaps for you to fill in if I flesh it out, but I suggest looking at a couple classes first, that way, if you like the archetype suggestions, it's a lot less work for me.
Sandman Bard Gives up some bardic stuff for other bardic stuff, but gets sneak attack
Stygian Slayer Loses some slayer talents and an ability that's basically worthless for your idea for UMD castery stuff
There might be a few others out there that are kind of similar, but they aren't coming to mind right now.
If those don't do it for you, then are you dead set on having level 9 spell progression? And would you prefer this to be more martial or more caster-like?
Bards more or less use enchantment and illusion, and they are 6/9 casters. There's a Bard archetype, Sandman, that gets sneak attack at a very slow progression. That's balanced already, so just use it.
Ninja'd!
I did just remember another archetype
Greensting Slayer It's a Magus archetype that uses its arcane pool to get sneak attack. I'm not all that familiar with it, but ability wise you might be interested in it.
No problem, I'd also suggest listening to LazarX's comment about building the race, and possibly thinking about Arcane Trickster. AT is less martial than I think you want, but it is pretty good for sneak attacking with spells, on top of being a full caster.
Alright so I typed out a bunch of stuff then lost it, but basically from what I can tell that falls under 15 RP which is advanced, which should be fine.
Some of the race stuff I feel is just stuff that you want for your build, rather than for the race in general, but I won't go into that any further.
The vestigial wings feel unnecessary, as you have wings that actually let you fly, and flying creature get an innate bonus on fly checks if I remember correctly.
I also only see rules for down to size tiny, not diminutive, and this size modifies +2 Dex and -2 Str
You are also lacking attribute modifiers from the race itself (Such as an elf getting +2 DEX/INT -2CON)
I think that was all.
I love Mass Effect and wanted to run a game in the Mass Effect universe. I tried to create some stuff but it was sod tough to balance then a flash hit me. I just re skinned 4e for my Mass Effect game, and in all honesty reskinning is the easiest most balaced way.
Maybe start with one of the above mentioned classes and make small modifications to it. Your GM seems not be cool to let you even broach the subject of home brewing a whole class so this may be an easier way to sell it.
Classes are one of the hardest things to design in this game.
Arcane duelist bard would also work well I believe.