What I have done when I’m looking for places to board is shoot an e-mail over, saying I’m looking for a place, do you have any open stalls for X date, and then usually ask the cost of boarding/training/whatever. That’s it, simple, easy.
Then, when I go see the place, I ask about what grain is fed, in your situation I’d ask how many pounds per day allowed and will they feed extra food that you provide or more of their own for an extra cost. I also ask about hay, what cut, how much do they get etc etc. Usually they show you the hay without prompting, so you can check out the quality. And then during your barn tour you can check out the stalls, bedding, water, turnout etc. Then I ask whatever other questions I might have, see if my horse will fit in with their program/turnout situation.
And if you’re around when staff are around, I’m sure most places would be more than happy to introduce you. Caveat: I’ve been at several barns that have staff from a variety of Spanish speaking countries (all legal). All of them have had an incredible, quiet, easy way with the horses, but to some degree many of them have been on the shy side, due to English not being their first language. (As soon as they find out I speak Spanish, that usually goes away!) So don’t be offended if they seem shy or standoffish, give them the benefit of the doubt!
But, in summary, I think a very basic e-mail is appropriate and not at all off putting, then you can get into more intricacies when you take your tour. As others have said, asking for all of that info upfront can be off putting. Any place I’ve boarded has been more than happy to ask all my questions on my tour.