The best thing you can do is run a wire directly from the alternator + stud to the battery.(or to the starter relay) This will take a lot of load off of the bulkhead connector. With this mod, the alternator will be charging the battery directly, instead of having to go through the bulkhead twice.

The next thing would be to add relays to the headlights. This will take even more load off of the bulkhead. It should also fix the problem of the lights dimming at idle.