Schandy hi shandy, editing lyrics on ST2 is not going to be any better than ST3 it might be a little worse as ST3 has some improvements as Peter said using a keyboard might help a little, using an imac is not the answer as the software performs in the same way as in ipad version its just bigger.
My suggestion is just edit all your lyrics in apples NOTES store them there in a folder MY songs Lyrics and just copy and paste them to ST3 lyrics Editor in ipad ST3 it also gives you a good backyp of your lyrics and auto syncs up with your other devices like iphone and imac so you automatically have your lyrics everywhere and if you edit your lyrics on any device its all automatically updated on all devices this is very handy.
You also have very easy access to all your lyrics from any other software.
ST3 is great for displaying synced lyrics but is a bit hard to use if you have timecode synced lyrics and chords involved, but if you only have lyrics NOTES IS A GREAT ALTERNATIVE.
You can edit on imac Notes and simply copy and paste from ipad Notes to ST3 on Ipad as it is automatically available to you on all devices.There are other small advantages but i have pointed out the main few.
Once you edit a few lyrics In NOTES and get use to this program you will get the feel of what ST3 expects and from then on it gets much easier and faster.
Reason why not to use ST3 imac to do your lyrics and if you use ipad to perform is you will allways require to Full backup on imac transfer your big file to ipad than restore full backup if you want to be all up to date with ipad so this will soon become a pain in your butt, so to save you a lot of time i suggest just use one device as your master and my suggestion is use the device you perform with as your master and enter all songs and lyrics on this device as it will save you a lot of time and confusion if youre up to date or not.
Just use the imac for very complicated audio editing then air drop to ipad, use NOTES for lyrics/chords as it is automatically up to date and available on all devices and use ST3 to fine tune your lyrics and enter timecodes.
This will be your fastest and easiest way to do things untill ST3 auto syncs to all devices, but i dont think apple will allow this as they only want this very handy feature for themselves.
cheers Damir