I've never really used power connectors before. I am working on a project and saw there are power connectors in it. We had some issues and changed the manufactured power connector to a 30A power connector. The system definitely needs more than 30A. Does the 30A really matter? Or should I buy a 60A connector instead?
You should use a power connector rated to carry at least the maximum current you expect it to carry.
Under the North American electrical code, it would be illegal to use a connector rated at 30 amps on a circuit where it would normally carry more than 30 amps.
Of course it matters. You need to give more information though. Current requirements, power requirements, voltage requirements, which connector you are talking about. If you pull 40A through a 30A connector there is a good chance of failure. It's also possible that nothing wrong will happen and the connector is just hotter than normal. We can't answer this without more info.
Ah, you might be able to parallel 30A pins to get higher than 30A, read the connector datasheet carefully and follow their recommendations to the letter.
Don't parallel connectors. They are probably not designed and tested to operate in parallel. Get one connector designed for at least 75 amps.