Of the two boards I use for foiling, only one has straps. I'm still undecided if the straps have any real advantage other that forcing my feet to be in the right position. On the strapless board, I sometimes jump backwards to clear the board and foil when crashing. Works great, but is not really an option with straps, since it could lead to falling onto the foil if a foot gets stuck in the straps.
I also really like the Slingshot suggestion of starting with a shorter mast to learn foiling. Crashes with a shorter mast are less dramatic and less likely to lead to injury. The shorter mast forces you to concentrate on controlling flight height a lot more than a longer mast. You can see that as a pain, or as development of useful skills. I find being able to fly low quite useful in overpowered and gusty conditions. With the 60 cm mast (and even more with the 45 cm), you pretty much are forced to learn when the foil flies too high and how to correct it before you crash. You also get lots of practice in recovering from breaches and spinouts without crashing. After that, a 90 cm mast is really easy

.