When you see a star that is 300 million light years away you are seeing it as it WAS 300 million years ago.?

Only in the vaguest sense, because you have several incorrect assumptions. First, you can't actrually SEE any stars that far away. All we see is the combined light of millions or billions of stars in a galaxy, no individual stars. Secondly, there is no telescope on Earth large enough to resolve the disk of any star other than Betelgeuse, let alone a planet revolving around a star.

The time delay is right - we see it as it was 300 million years ago. (with no corrections for Red Shift) (there should be a small correction at that distance).

There is no way to get the resolution at that distance to see anything much other than an image of the star.

Yes

You're correct. For example, we see the Andromeda galaxy *as it was* 2.2 million years ago.

Yes because of the time it takes for light to reach us.

yep, and guess how many years for us to invent wheels to an electric sports car

What would our sun look like from Betelgeuse...........