Jittery Text Motion Tween and Quality Loss in Imports

Howdy hello! I am brand new to this program so these questions are probably annoyingly simple. I swear I browsed this forum for topics that could answer this before I went and posted my own, but I could not find the right one (or they were super old and unanswered).

I am having two problems up front. I am trying to do some very simple tweening based animations with a logo. I'm starting off with scaling it up across the span of two seconds.

I first imported the logo itself, a very high quality PNG file to the stage. The tween was nice and smooth, but upon importing, the quality was lost big time. It looked like a JPEG. Tested it by exporting it to see if it was just the preview; still gross. Imported a different high quality PNG to see if it was just that one image; still gross.

So, instead I tried to recreate the logo in base form with the text tool. Visual quality was great..until I added the motion tween. In scaling up it was very very jittery. It was like a train was going by and all the letters were vibrating at offset rates as they were getting larger. The position/anchor point wasn't moved, and the layer was converted to a symbol prior.

I'm a bit at a loss aha. I would highly appreciate some assistance!