Best advice I have for this is, don't let others influence how you and your future spouse plan your wedding. This day is 100% about you and your spouse! If someone is causing you extreme grief during wedding planning, be it your MOH/Best Man, Bridesmaid/Groomsman, etc then don't have them participate in the wedding. (Note I say extreme grief, like you have cried/fussed/cussed about it for months, explained your feelings/talked to this person, and they still keep causing you more grief, and you are to the point that you fear that your wedding may go sideways if they are an attendant).You don't have to mean about it, just simply tell them that they seem like they don't have the time/want/desire to participate and you don't want to put that kind of pressure on them. It is important to stress to them they are important to you, but you feel it's best they come to your wedding as a guest without any expectations/dress code/etc. If your parents want to relive their wedding through you, but it's something you don't want to do be honest. Simply say, Mom/Dad (Grandpa/Grandma whoever) We don't want that for our wedding. If they are paying and are demanding you do certain things that you just don't feel are a good fit you and your future spouse, then maybe it's time to hit the brakes until you and your spouse can pay for and have the wedding you want, and dreamed of. Also, whatever you do, don't have family members working as a vendor the day of the wedding. The day before helping to decorate is fine, but don't have a family member or even close friend do things like photography, videography, catering, make your wedding cake etc. This is bound to lead to some letdown in either quality, turnaround time, etc. Hire a professional and make sure you have a contract with the delivery/due date of your purchase listed. Otherwise you may be waiting for a year or more, before you have any photos, video, etc. from your wedding day.
This is what I wish someone would have told me prior to our wedding. Looking back on our wedding day for both my husband and I isn't what we wanted. We focused more on what family wanted, friends feelings, and overall guest experience. We lost out on a lot of the things we wanted due to being told things like, "if you have it there we won't come because it's too far to travel", "Well you should do this, this way", etc. We gave up our dream wedding venue/location, to accommodate his family, and some of our friends. Looking back we both wish we would have done a lot of things differently. At one time, we talked about postponing our wedding, and now looking back we wish we would have. This is a special day in everyone's life, and it's about you and your spouse starting your new life together.
This is not mean you won't have feelings of, I wish I had done this or done that. Every wedding has something that goes not exactly according to planned even with professional help. I hope that this helps you to plan your dream wedding. Congratulations, and Best Wishes.