Electrical issues are always a nightmare and it may well be you have more than one fault. If anyone can decipher the wiring diagram then it's Richard V6.
A couple of thoughts from me:
With the fuses blowing something is shorting or feeding in reverse most likely due to a bad earth or connector.
You mentioned the headlamp main beam doesn't come on when you push the indicator stalk so swap out the main beam relay.
Carefully check the connectors for the TSM and engine to chassis loom. It's possible one or more pins in the plug or socket have bent or been pushed into the housing or corroded.
Check all the earthing points for the chassis and engine loom. Hopefully Richard will be able to tell you from the wiring diagram how ma y there are and possible locations.
