I’ve used SQL Server since version 7, but, still, please regard this ‘answer’ as slightly-educated guess (;

all should work OK (v.2008 is fine) – assuming the bugs are worked out (don’t install on the first day it comes out) I usually use the most recent version.
Management Studio gives you a UI to investigate/export/backup the database (I also use MS Access)
My logic: SQL server is used in many high-end implementations world-wide – the incremental upgrades are often useful, particularly from the Management Studio standpoint, and more and more bugs are killed (unfortunately some get added, too)
I use, presently, 64bit 2014 Express with Management Studio – what MS Downloads calls
( ExpressAdv 64BIT\SQLEXPRADV_x64_ENU.exe )

I make sure to use all 64bit MS products on this machine, because there are incompatibilities with mixing Office versions, in some cases, and I value having MS Access on this machine, which allows me to manipulate SQL Server databases in a familiar Office UI type environment.

Irregular updates to SQL Server are sent out on Windows Update. It is likely that sometime after SQLSvr 2016 comes out, 2014 will get some updates rolled out.
Personally, I will stick with 2014 in this TABBLES environment for another year, probably.

hope that helps