Great you got it to fly straight
Regarding power and trim, all kites are a bit or a lot different, also after use.
Having lines equal length is a good starting point, but that's it.
As I assume you have, or at some time will get, several kites, it is not a good idea to trim too much at the bar, as it must fit all your kites in perfect trim.
Simply make the rear pigtails at the kite a bit longer, or make some knots on the front bridles if possible.
This way you can use all bars with all kites
Peter