can't help with the azalea - other than to say we had them
growing up and they were in full sun for most of the day...the bushes are currently over 50 years old and still going strong!!
you can get some peat at any garden center. i'd add some in the hole when planting - doesn't hurt anything!! what site did you go to that said to use rhody food?? i wouldn't worry too much, use the stuff you bought.
thing is, you need to get them into the ground soon, so work with what you've got on hand. if they're nice healthy specimens, they should do just fine.
gladiola's are terrific!! they come in a good variety of colors. mine are a deep magenta - really, really lovely! i've got them out front and in the back yard. those in front have shade until midday and those in back are in full sun until late in the day. both sets do wonderful! i've heard you're supposed to take them up in the fall. i never have and they come back every year. i DO put down a good, thick layer of leaves in the fall tho, so maybe that's what's been saving them? or it could be the
zone i'm in. dunno...it's working tho, so i'm not changing a thing!
oh, they get real tall so they should be used at the back of your bed - and planted preferably so that they are against something so that you can give them the support they need. i've got mine next to the fence in the back and in the front they're in front of the porch - which is raised up from the lawn so they lean against the wall.
heavy rain/wind will knock them down, so, you might want to stake them. i tie them to the fence - those in front of the porch are in a more protected spot and i've never had a problem with them falling over.