As long as that fuse has been replaced and is not continuing to blow out I would think that it is unrelated to your current problem.

Between the hesitation when turning on your accessories and the click click when trying to start I would say that it sounds as if your charging system is kaput. The hesitation probably occured when the battery was getting too low to run the ignition and injection properly and now that the battery is too low it can't do more than click the starter solenoid.

It could just be a coincidence that the charging system has gone out at this particular time or perhaps it is related to your mods.

Check to see if your alternator light comes on when you turn on the key. If not there is some sort of problem.

If you have a voltage meter connect it to your system once the car is charged up again and running. If the system does not have more than 13.5 volts when the engine is above 2000 RPMs you definantly have a charging system problem.

On my porsche the alternator light is used to pre-charge the alternator windings so if that light burns out or is disconnected my system wont charge. I would assume that your modern system would not have such a circuit, but you never know.