#1
B - MAN

My Main Rig:
☺1998 Gibson Les Paul Studio DC
☺Reverend Rocco(USA)
☺Martin DM
☺Peavey ValveKing 112
☺Dunlop Tortex(1.35Mm) Picks
☺Everly Rockers - .10guage.
☺Martin - .11guage.
☺Too many effects to list.
#2
#3 is a good one and normally $200 on the dot but they have a lower price for a while so i suggest that.

Use a condenser or SM57 for acoustic guitar recording...an SM58 wont really pick it up too well and is mostly used for live vocals.

for the studio, an SM57 is great paired with a pop filter because it can record so much with a good preamp which your mackie interface has
#3
58 can do basically the same job as a 57 you just need to eq above 5 khz a bit *shrugs* 57 is cheaper though... then again if your paying the difference for a pop filter it hardly matters
#5
The 57 and 58 have no noticeable difference if you remove the windscreen on the 58. Even with the windscreen, the difference is minimal. The two can be used interchangably in a studio.
57:

58:


that's the difference. The presence peak on the 58 starts about 1k lower than the 57, but trust me when I say you hardly notice the difference when comparing them side by side on the same source, so you're not going to be using a 57 and think to yourself 'damn, I really wish I had a 58 for that'. The difference is minimal. I would take a 58 over a 57 though, if only for the windscreen which comes in handy live. According to the diagram the 57 records slightly higher frequencies, but once again, the difference is minimal in reality.
#6
So an SM58 is usable for recording?
B - MAN

My Main Rig:
☺1998 Gibson Les Paul Studio DC
☺Reverend Rocco(USA)
☺Martin DM
☺Peavey ValveKing 112
☺Dunlop Tortex(1.35Mm) Picks
☺Everly Rockers - .10guage.
☺Martin - .11guage.
☺Too many effects to list.