#1
Could some one please tell me what key/keys, these chords would fit in: Aadd2, F#madd2, Dsus2 and Esus2.

I've been trying for about the last 10 minutes and i just can seem to get it
#2
Looks like A major to me, if you look at the base chords with no add stuff. but it should still fit in fine with A major.
#4
for the record add2 = add9 regardless of where it's voiced.
Aadd9 = A C# E B
F#madd9 = F# A C# G#
Dsus2 = D E A
Esus2 = E F# B

Sharps = F# C# G# = Check circle of fifths key = A major
A B# C# D E F# G# A
Si
#6
No worries. You should check it out. I just glance at it now and then and it slowly sinks in when you start to work out keys more often. When you start to see patterns with the semitone placements and the order of sharps and stuff things really start to click.
Good Luck
Si