You can put your cursor inside the general macro that you want to copy and push CTRL-A, that selects all the text. Then go into the char macro text area and push CTRL-V, that is paste. Or you can just highlight the text you want to copy and push CTRL-C and then CTRL-V to paste.

I use about 3-5 macros total. Some are extras, but not a lot.
Attack:
/startattack [target=focus-target]
Heal:
/castsequence [target=focus-target-target] reset=15 Lesser Healing Wave, , , , Lesser Healing Wave
Misc:
/castsequence [target=focus-target] reset=7 Earth Shock, , , , , , ,
Totems:
/castsequence reset=combat/25 Stone Skin Totem, Healing Stream Totem, Grounding Totem, Searing Totem


Others are just multiples of totems, so I just put the totems in the slots--no macro needed (all searing totems, mana/healing totems, etc).

So with just a few macros you can do almost everything you can do. Some extras are Chain lightning and chain heal off the focus-target-target and focus-target respectively. Still about 8 total. So my suggestion is to condense macros by using [combat] and target='s.