I think you need to listen to the advise and try all until you find what fits you and what kind of music you want to play. The DAA vs DAD thing is a big debate. I would agree the DAA might be a beginning tuning--BUT only because teachers have started students out in it. Actually, for ease of chording and getting harmony, DAD presents less difficulty. You don't have to skip over a string to get a chord. If you want to chord, it would be well to learn standard finger/fret position: these position apply all the way up the fret board. Also DAD tuning allows easy slimping into DGD or DAC. The problem with DAD is that many tunes go below melody D and beginners have developed the skill to cross string the melody. Also, if you are playing with other instruments, the melody on the middle and bass strings (if you are strumming) gets lost. Dulcimers usually don't have enough volume to project it. Also, DAA tends to have a little deep sound and may be more pleasing.
As far as strumming the issue should be what you want to hear first--the melody or the drone.