Shots #1, #3 & #5 look to be shot with natural light.
#1 is great - but perhaps just a little busy with the blinds. The thing I love most about the shot is the soft lighting.
#2 looks like they have been blasted with flash a little too much. Would have been hard to shoot - particularly from thta angle as the bride and groom are quite contrasty where as the decking seems not to be.
#3 I like the soft lighting you achieved with natural light, but the mix of light sources has given a couple of different colours - my second favourite image.
#4 as #2 - looks like a strong flash hit. What setting was the flash on? I imagine you would have had trouble with any auto settings on the SB800 given the subject matter being at both extremes of light and dark.
#5 - a tricky one with the lighting you had to work with. A tighter crop on the hands may improve it - and maybe a bit of dodging and burning or if you are using
PSCS then
moderate use of the highlight shadow function might balance the lighting a bit better.
Was this the wedding you were doing a few weeks ago?