IMO, the blocks aren't so bad. Your photographer should be able to shoot around the blocks if you hate them, or incorporate them in some fun photos. Talk to your photographer about your concerns.
Will you be setting up chairs in pavilion that is pictured? You could check into renting a wheelchair ramp, which will make it easier for grandma and other guests to access the pavilion.
It seems unlikely that the venue will move the flood wall for your wedding.
I see on the other thread that the venue coordinator has suggested they may be able to move the blocks before your wedding. You should ask her if they can rent the ramps or reimburse you for the rentals. If they know you have guests with mobility issues - one more reason to move some of the blocks, at least.
Re: .
Will you be setting up chairs in pavilion that is pictured? You could check into renting a wheelchair ramp, which will make it easier for grandma and other guests to access the pavilion.
It seems unlikely that the venue will move the flood wall for your wedding.