I'll tackle the second problem first. Check your "race_name"_AI_Settings file. Look for "Max Ship Size Tonnage From Start 1(2,3) Amount := " and see if it has a tonnage listed. If it does change the numbers to 0. When I was doing AI testing it wouldn't build ships over the tonnage specified here for x number of turns, even on a high tech start! Hope that helps.
Now for the first problem. The only thing I can think of would be if you've got a QNP system in place. You might have to increase your min/max desired speed. If that doesn't work you can always call for engines as a must have ability.
