1-
Mapeikar is probably the closest you'll get. Don't forget English has a lazy vowel phenomenon: native speakers choose the most important 40 to 60 % of the syllables and pronounce them quite fully, with the others being run on and simplified to a schwa.
You are right about lazy vowel thing, but in this case we are doing the inverse process by writing new words from their original pronunciation. so I think we can't (shouldn't) skip the H letter.
2-
'Mahpaykar' might work.
/aeh/ and /aer/ don't exist at the end of English words, so they would be a problem.
/eɪ/ is always going to be a guess for English speakers - it could be /eɪ/, /i:/, /aɪ/ (as in German).
You're still left with where to put the stress.
PS: I just thought of "Ma Baker, but with a 'P'"
Actually it is /mæh/ which means "moon" in Persian and /peɪkær/ which means "body" or "statue" and /mæhpeɪkær/ means "moonlike body" and the stress is on its first syllable.
/peɪ/ like "
Pay" and /kær/ like "
Character"
Ma Baker : It's prononciation is very close to mine and also I love that song performed by Boney M :-D
3-
I think generally people will accept the spelling they're given by the person. There are several spellings for Mohammed/Muhammed etc- I just use the one the person uses.
I think it is something statistical. if you write a name with different spellings in Google you will see how many people use that form of spelling.
for example my first name is "Navid" = /næviːd/ and google shows a result of 3 millions for "Navid" and 2 millions for "Naveed" which means no compromise. However a rock band called Our Lady Peace from Canada has a song and album called by my name and they've prefered to write it as "Naveed" and I think it is correct since it has /i:/ sound and also Navid may be pronounced like David by those who never heard of that. but I keep writing it Navid because of its simple and acceptable form.
What do you think of that?
4-
One more thing about text-to-speech: Microsoft TTS pronounces "baker" like /beɪkə(r)/ , replacing b with p results /pækə(r)/ and it is interesting to me that Microsoft TTS works fine with English words but a little change in the word has such effect on the outcome.
why is this thus?
5-
At the end, still I haven't get any proper spelling for my surname, but I think it should be among these :
Mahpeikar, Mahpeykar, Mahpaykar which one do you suggest?