I'll try to answer your questions

1) They don't really have a family name as in Vanilla, the ar e just ''The Romans .

2) You can Built Saturnus, Jupiter , Neptune ,Mars and Ceres.

3) no gladiators and I havce never Built decers in the game ( in vanilla and RTR ) so I wouldn't know if you can build them, I do think so actually since it requires a awsome temple of Neptune ( I think ) which you can build .

4) no they aren't powered down, not every general travels by foot , only the Roman and the Dcian and greek generals have I seen on foot , they are definatley not underpowerd ( is that a word ? ) less mobile yes , but that isn't really a problem since it is compensated by high attack stats.

5 ) they have only removed the fantasy units such as arcanii , but they have included lot's of units too , just as they have reskinned a lot of units.

6) Wouldn't know a lot about this, I do know that you nowe need timber to build ships ( or is that 6.0.... ) and I recall that you need stone for walls....
Not certain about this maybe someone else does .

7) you can get a gaius Julius and probably a Hannibal Barca.. but don't think that you will be able to use Ceasar in say 50 BC..

8 ) never bothered me.

9 ) yes


Haven't played RTR n a while , so someone else should fill in or correct me if I said some wrong things

Hoped this helped though.