When i got married i did something similar and no one thought it was rude, but i didnt tell them it was mandatory just mentioned that we where saving for a home blah blah and money was wanted... i think we only got a few gifts which was fine to. i think you can mention it but choose your words carefully and it should be fine.
As for a realtor honestly you are smart to ask because i think we went through 5 realtors before we found the one we really liked. Not sure where you where looking to buy a home in california but we live in Laguna Hills and it is beautiful. Our realtors name was Angie and she was awesome and I would recommend her to anyone. She specializes in
first time home buyers and
Orange County real estate.
I hope this helps! good luck and congrats on the big day!