Regarding your first question, you can save your engine configuration (right click on the engine part of the project), save T1, T2, T3 or whatever separately, then you can load up each Tier in the future really quickly - or create a 'dummy' tiered project kept Inactive and duplicate that filling in the details for the new site/URL. You can also use Notepad++ (see https://forum.gsa-online.de/discussion/comment/60909#Comment_60909 and other threads by ron) to modify/edit projects in bulk.
Spinfolder macro as Sven said is much better to use in my opinion than loading 100s of spun articles in SER as you want to keep the amount of files to a minimum in SER for optimum performance. I pull articles using %spinfolder% from the desktop or Dropbox (the latter is handy if you have multiple copies of SER and servers).
Comments
1) not yes, still on to do list...you can use %spinfolder% macro till then.
2) just on a single project.