Jack,
The couple of replies so far haven't been 100% accurate. I suggest that you learn to find your way around
LASORS, and check all the requirements for anything you want to do in that document.
- First of all, your instructor rating. It is true that you can't do your FI rating at the same time as your PPL, because you will need 200 hours experience, including 150 hours as pilot in command, before you can start your FI course.
- You do
not need a CPL to be an instructor. You only need a CPL if you want to be
paid to instruct.
- However, you will need to do either the CPL or the ATPL written exams, regardless of whether you want to be paid or not.
If your long term aim is a career as a commercial pilot, then you should probably do the ATPL written exams. These will enable you to get a CPL, an IR, and - once you are sufficiently experienced on multi-crew aircraft - to upgrade your CPL to an ATPL. (If you did CPL exams instead of ATPL exams, you'd then either have to a) take the ATPL exams before you do your IR, which will mean you'll have to sit several of the exams twice, or b) take the IR exams before you do your IR, which won't be valid for upgrading to an ATPL, and will mean you're not eligible for a lot of jobs where ATPL exams are required by the employer.)
The only snag that I see with your plan is this: once you take your ATPL exams, you have only 3 years to get your CPL and your IR. After this, the exams stop being valid, and you'll need to re-take them. So even though you're not thinking of flying commercially for 10 years, you'll need to get an IR considerably before you actually need it in order to avoid a lot of extra work/complications later on.
Of course there is no way anyone can do anything but guess what the job market will be like in 10 years time.
On the subject of US Visas, I'm afraid I don't know enough to really comment.
Good luck!