They probably do not want to sour your experience with not fully balanced DG's. Either they are too strong and get balanced down and you hoot and holler about it or they start out too week and then you rage for the opposite reason.
Avaj
I used to start with the vasari carrier cap ship since I liked using it's heal to keep my frigates alive early. I didn't know how good the egg was at the time. I also later found out you can send your cap in first so it gets targeted and have your frigates follow. I still build the carrier later. I am sure it is the reason I have low casualties vs AI. I also like the antorak marauder. Giving your fleet extra speed helps out more then you might think. 
It will be eating them because they are as good as dead if they are in it's range.
With the temporary phase stabilizers the base and capital have you can only bring reinforcements. You cannot use it to head back to a permenant stabilizer.
I like being around 1(long) jump away from anywhere with the Vasari. It allows you to have a larger strike group since you don't have to have your fleet as spread apart. When all else is fairly similar speed and information is key. I do however really like the feel of the Advent. Nice huge guardian shields and all. The capital with provoke hysteria is amazing at bombarding a planet. If you haven't seen it you are missing out on it. Completely change