Hi Ben, glad to see another TSX'er in Qc!
First I would suggest to check into 06-08 models as they have some improvements over 04-05. If you plan on modding, then 07-08 will be your best bet.
Apart of this, grinding issues is persistent on 07-08 models but, if you change your transmission often, it will help.
I also experience the moving driver seat problem but, unfortunately there is no recall for the power steering hose in Canada. Mine is not leaking and if it does, I would change it myself.
With our poor roads in Quebec city, I would suggest to verify the lower arms bushings and other direction components as mine started to deteriorate a little.
Anyway, how many kilometers on it?
Are you looking for an auto or a manual?
Good luck!
J~