lookin' good so far!
for the glue, one thing i do pretty often is mix glues... use one quick bonding thing like superglue or even hot glue to hold things in place. then use a slower setting, stronger glue for the real strength (like goop)
for plastic Plumber's Goop rocks.
also, if you are trying to bend the pieces into shape and glue them, try heating up the plastic a bit first.. it will help it curve into shape and stresses the glue less. just don't overheat it!
i really want to do a scratch build some day. it reminds me of when i was a kid and couldn't get the toys i wanted my mom to buy me... i'd cut up carboard boxes and make my own, and half the time they were more fun than the "real" ones! 