Welcome! I'm pretty new here too but also new to Oldmobiles (it's my first).
As for ecotec oil usage issues, I know that GM decided to replace their conventional PCV valve with a fixed orifice design built into the engine (most commonly the valve cover). That's about all I know and oil burning issues are still a problem with this new design (even worse in some cases than before).
I'd search ecotec oil burning and see what the cavvy/cobalt guys have figured out. If it was me, I'd be looking into cleaning it out if possible. might help with some issues.
1999 Alero GL Sedan - 3400/4T45E
-HP Tuners custom tune in the works
-Hopefully much more in the works besides maintenance.