DON'T use silicone modelkid! I think you were kidding but it will never completely harden adn paint won't stick to it for long either.
Just get some super glue. It really is easy to use (it's all I use now, even for assembly) just let it dry then start sanding. The key is don't let it dry over night then try to sand. It will be extremely hard and if you don't have a good precision mini-file or something like that it's easy to sand more of the kit than the CA glue. The nice thing is you can fill and sand a seam in a sitting and be done without waiting for filler to dry, sanding and refilling because it shrunk. etc. etc.
Give it a try, just do a little at a time and get the hang of it.
Eric