Hi Bob
I haven't had much time to do anything serious with this yet. I've got the free MobileSheets version also and have only tinkered with it without reading the manual.
I can tell you that your issue about annotations only working in that app are going to be updated according to the forum on his website.
What I have discovered so far regarding pdf apps is that you can make edits on Adobe but I have found that program renders the music too slowly. I just got an update on it maybe that will help. Otherwise, the fastest app for rendering a pdf I have found is Radaee PDF Viewer, which I discovered also has editing features. Both these apps will show your annotations on your computer I have found using Adobe and also PDF-XChange Editor. PDF-EChange also allows you to edit on your computer and what you save will work on your tablet. This is something I was really hoping I'd find and this is the combination that seems to be best so far.
Also, although one may exist, I have not found one that does everything, such as you mentioned tap on a page to turn it. For this I have discovered a popular app called PDF Reader. It has 5,000,000 downloads. This should tell us a lot right there. I do not believe it has an edit feature but using a combination of a couple apps is a workaround that doesn't bother me.
As far as set lists while not using MobileSheets, which has great features for things like this along with whatever category you want to use whether alpha, genre, etc., One could use a PDF app and have a gig list folder. In the simplest form they would be in alpha order. But, another way is what I have done occasionally on my laptop, which is to use PDF Split and Merge to make a gig book with one song after another in the order you choose. It is easy to do and doesn't take long.
I'll include some links to these apps to help you get started.
Adobe Reader with editor:
https://play.google.com/store/apps/details?id=com.adobe.readerRadaee Viewer with editor:
https://play.google.com/store/apps/details?id=radaee.pdfPDF Reader:
https://play.google.com/store/apps/details?id=com.foobnix.pdf.readerPDF XChange:
http://download.cnet.com/PDF-XChange-Viewer/3000-10743_4-10598377.htmlPDF Split and Merge:
http://sourceforge.net/projects/pdfsam/MobileSheets site with forum etc:
http://www.zubersoft.com/mobilesheets/Hope this helps.
ScottL