Hi Michael,
I didn't have any problems getting the form showing the tax was paid. The frustrating thing is it seems to vary from region to region! The guy I did it with didn't seem to know much about it, and even questioned if I needed it. Get it though just in case. Never heard anything about having to be a resident tax payer. However, are you doing this as a private individual or through your company? Who is the registered owner of the bike?
You're right about the controle technique - not needed! BUT, you're certificate de conformité European from yamaha (you do have one right?! It's expensive about 120 euros) will only be a partial one, and will state you need to change the lights for driving on the right. Buy a second hand light unit and do the work yourself (it's easy and I can give you tips if you need it). You'll then need to have it inspected to confirm it meets French standards at the DREAR - basically for about 80 euros some guy looks at the light for the E13 mark on the glass, and sends you the paperwork about a week later.
So once you've got that you can go to the local Mairie and register your bike! It's expensive, and price varies from region to region, I think I paid about 120 euros. You'll need:
Tax paid certificate
DREAR inspection paperwork
Certificate de conformité European from Yamaha
Your Irish registration docs
Proof of address
ID
Your previously filled out french carte grise application form.
It's complicated, expensive and an administrative nightmare! If I did it again, I'd just sell my bike in the UK and buy a French one here.
Let me know if you need more help or info.
Dave