Well, first of all, we'd need more information about your game before we can comment on it, sorry.
From the little I can discern from the map, you seem to play a high-expansionist style of gameplay. I wouldn't suggest ever taking that many planets unless starting with more than one planet, because of command station caps.
When I expand in my games, I often do not get more than 17-25 planets because of limits on the mark II and III command stations. Any more than 17 or so planets will have diminishing returns (because your command stations will be subpar and have miniscule resource returns).
If you could give us more information such as the AI difficulty level, AI type, minor factions, and any other settings, it would certainly help in getting your more useful advice.