ROB is my second, but I still want to find ways of improving it. Anyways, here are my videos: (I know they may seem outdated, but I haven't got the time to record a fresh match)
ROB vs Meta Knight
http://www.youtube.com/watch?v=nCuqY6ot68Y
Rob vs Lucas
http://www.youtube.com/watch?v=ZmEbnQ_Z3ec
I mainly watched the match vs. Lucas, here's some things I noticed
-You roll. A LOT. ROB's roll is really not all that great, it's slow and punishable, and should only be used to retreat, not to close the gap.
-Going along with the rolling, you seemed to want to roll behind him to grab a lot. ROB is not a grabby character, you really should only grab if you shield grab someone. It's just not worth the risk to be close to them like that, just to get a grab that you don't really need. =/
-You seem to throw out a lot of d-smashes, sometimes out of no where. d-smash should really only be used out of spot dodge, but not every time. If you use it too much, it becomes predictable, and you will get punished for it.
-Do you use the C-stick at all? The spacing on your fairs could be better, you should try to hit them with the tip of ROB's hands, so you won't get punished as easily if they shield. Going along with that, the few Nairs you threw out could have been spaced better too, try to hit them with the tip of the flame, you seemed to dive bomb into them with it.
-When you got him on the tree on the fire transformation, you can d-tilt lock him, it's a nice option when you have someone's back against the wall. This works espcially well on Lucas. You got two grab releases on him against the wall, Lucas has so much GR lag, that you could have easily set up a d-tilt lock.
-I don't feel like you used enough gyros and lasers. Those are ROB's bread and butter. They should be used to keep enemies away, espcially the laser at long distances. Going along with that, if they don't approach you, don't be afraid to shoot your projectiles at them. There are very few times where ROB actually has to approach, unless he is facing Falco/TL/another spammy character that can outcamp ROB.
-One of the positives I noticed was that you make a good use of U-air, and the projectiles you did use were used effectively. =D
-Also, I'm sure this one is fairly obvious, but avoid Side B, especially offstage. ^_^