i dont know about 1, but depends on the school you applied to, sometimes they accept transfer credits up to a certain limit.

for (2), i can tell you as a follow mechanical engineering student, the 1st two years of engineering classes are pretty basic in most college, it will be, in your case, calculus, static, dynamics, and probably circuits. If your community college offers these courses, u can probably transfer it over. However, a lot of high level engineering classes have pre-require courses. If you are missing these courses, you should expect to stay in that university for more than 2 years.