To answer some of your questions:
a) You have to complete the multi engine flight test in an actual airplane. You cannot take the test in simulator. This need not be a 737 or 787 aircraft...a light piston twin aircraft rented from a flight training unit will suffice.
You will need a letter of recommendation from a qualified instructor to be eligible for admission to the test. Notwithstanding your substantial experience, I suggest an instructor would want to see you fly once and manage the flight test drills prior to sending you for the test.
b) The exams may be written in one region and the results used for an application made in a second region. As an example I live in Calgary and wrote SAMRA in the Calgary office (Prairies Region). I wrote SARON in the Vancouver office (Pacific Region) during a brief trip there.
Ultimately my application was sent to the Prairies Region office in Winnipeg for processing. I completed the form, send the fee, the letters showing my test results and logbooks to the Winnipeg office. The more stuff you include and the less they look up the better it seems.
The question of where your application will be processed is probably the more complicated one, as it seems you are not a resident of Canada. Normally your file is held in the regional office where you reside. If you don't live here, would might be able to work around this issue by using the mailing address for a friend or relative.
c) Call the test center you intend to use to ask about booking a time to write the examination. Calgary's test room is small and the computers used for the test must be booked in advance. I do not recall whether I need to book a time in Vancouver.
d) Submitting your logbooks is safe (although I would make a photocopy as back up). I sent mine in via courier and they were returned to me by Transport Canada via registered post. If you would like them couriered back to you then include an international prepaid return envelope for this purpose.
Be forewarned. Processing time is promised to be 90 days in the Prairies Region. It took them almost exactly 90 days to be processed and return things to me.
e) You must complete a multi engine instrument flight test (or pilot proficiency check if you have already passed the initial flight test) no more than one year (365 days) before the application for an ATPL is submitted.
You will need a letter of recommendation for the flight test from a qualified instructor.
The multi engine instrument flight test (or pilot proficiency check) CANNOT be completed in a flight simulator. It does not matter if it is a full motion or category D sim. The test has to be in an airplane.
A few other things to consider...
I) Do you possess a Canadian Catagory One medical? You will need one to hold the ATPL.
In my experience, one's first interface with Transport Canada begins with the medical which opens a file number which later becomes your license number. If you are already applying for license conversions perhaps you have this already, if not. I would start there.
II) You seem to be hoping to have your type rating added to your ATPL. I am not certain whether your current type rating from your current employer's home company will transfer to your Canadian license. If not, you will need to pass a PPC here to gain the endoresment. The only way to add a type rating for an advanced aircraft like this would be through a company sponsored training and PPC program...I am not sure how you will be able to work around this.
Returning to your original questions about the ATPL process....Looking at what you intend to achieve I would recommend writing and passing all the exams first and then spending a few days in Canada at a flight school.
You will need to get your Canadian license issues, write your tests, pass your multi engine flight test, get the multi rating signed off and then pass your multi engine instrument flight test to have these endorsements added to your Canadian license. Once again - you cannot do much of this in a sim. It has to be a real airplane.
after approved, go to a 737 sim to do the Stand-Alone Checkride (Multi-Engine).
I am starting this process very soon, and there are my questions:
1) These tests SAMRA, INRAT and SARON can be done in one region, and the process itself done in another region? (Ex: Make these tests in Vancouver, Open the process for the ATPL License in Winnipeg, and SIM at Toronto??)
2) To perform the written tests is just approach any applicable Transport Canada Centre or Authorized Examination Invigilators, during working hours, OR these tests are done at fixed dates? Do i need to schedule it in advance??
3) Regarding submit the logbooks, is it safe?? how do they return it to the applicant, or do you need to collect it after ready?
4) Do you know any 737 SIM in Canada that i can use it for this purpose?? The 787 SIM of AIR CANADA seems to be exclusively for them. Unfortunately..
Thank you guys, it is everything new for me, deal with this stuff, but i hope that someone can light my head, and help me with these questions.