I've loaded my Kemper both ways, vertically (with the strap facing "up") and horizontally (with the flaps being the "front" and "back"). I found that horizontal does allow for a tight fit and you can leave in the bag while playing (which I've done). Now saying that, I've moved back to vertically because of two reasons: first, I use a power head into a cabinet so while leaving in the bag is good, the "front" and "back" flaps cover part of the cabinet (and if I fold them and put them under, it makes for a non-stable base for the Kemper). Second (and more importantly for me), one day I forgot to zip up the "back" and the Kemper fell out. I'm happy to say it was not damaged, but that made me paranoid enough to go back to vertical!!
The only other thing I will point out is, when in the "horizontal" position, unloading and loading into the bag stresses the inside fabric and I've noticed small tears because of it...
The Toaster will fit in the bag horizontally?? Never thought of that, will have to try it. I've always put it in vertically and piled stuff on top as well as selected padded stuff between the front of the toaster and the case (there is a bit of a gap in there as well).
I used to put it horizontally but nowadays the remote goes on top and that wouldn't be a healthy combination 
