As for colors, you may want to put the guys all in claret-colored vests (and potentially having the groom's with a pattern and the groomsmen without) or you may want to have the groom's vest in ivory and the groomsmen in claret. Go to your local tuxedo shop and play around with various combinations until you find one you like the best.
Yes, I think having the ties be the same color would be ideal. However, you may want to have a little pattern on either the vest or the tie using the same colors to jazz it up a little. Personally, I like the look of the patterned vests with solid color ties but that is just me. Any combination would be appropriate.
I think the blush shoes would be lovely with your dress, especially since it has blush accents. Bridal shoes can be as fun and formal as the bride likes it is entirely up to her discretion. Some brides wear flip-flops, sneakers, combat boots, etc. under their dresses. I had a white wedding dress with beading all over it, giving it a very sparkly appearance.
My wedding colors were silver/platinum and baby blue. I chose light silver colored shoes because I really liked the shoes and I thought they went well with the sparkly aspect of my dress (not to mention were in our wedding colors). So feel free to get the shoes.
Just make sure to walk in them a bit to make sure they're comfortable. Once you buy them, break them in a good bit as well so they'll be comfortable for the reception. My shoes had a 2 1/2" heel (I'm 5'4" and my husband is 6'3") but I was perfectly comfortable dancing the entire reception because I had broken them in a bit by walking around my house a few weeks beforehand.
For a 'traditional' formal daytime wedding, the groom can wear a "morning suit" which consists of a cutaway coat, striped trousers, white wing shirt, gray vest and an ascot or four-in-hand tie. The groom's attendants and both fathers should be similarly outfitted, though they can choose different ties from that of the groom.
For a contemporary ultra formal daytime wedding, the groom may select a cutaway, stroller or tuxedo jacket. Fathers should be dressed in matching cutaways or tuxedos. If the groom wears a cutaway, he may still have the other wedding party members dressed in a stroller so the groom will stand out.
Obviously he can also have a matching vest (waistcoat) and or tie/cravat in the colors of your MOH etc.
In these modern times, color doesn't indicate the 'formality' of clothing when it comes to weddings. In all honesty, black isn't going to complement the colors your friend has picked. You can get some very smart suits in chocolate brown.
Tell you what, if you can give me the gowns style number and make and I will take a look at the gown. I can then advise you a little better in reference to suits and what would complement well.