jblank wrote:Greetings, just a few questions that I am sure you Vets can answer. Thank you in advance!

Hello jblank, welcome to the forums, I'll see if I can give you some quick answers.
1) What are "Core" units?
A 'Core' is the collection of units a player can carry over between scenarios. They are 'your' troops. A scenario allows the deployment of a limited number of units, so-called 'core slots', but your actual core size can be bigger. This can be handy in case you don't want to deploy certain (specialized) units but still want to field the maximum number of troops.
2) What are "SE" units? Like I got a Gebirgsjaeger inf unit and it has SE on it.
SE are elite 'bonus' units, they are randomly awarded to the player. They are added to the core, but can always be deployed independent of the maximum core slots allowed by a scenario, so each SE unit effectively increases the total size of your fighting force. There is a limit as to how many you receive, dependent on your progress in campaigns. Early on only one or two are allowed.
3) Can you see what individual units were killed during the battle, in case you lose a Hero unit?
There is a cheat, called 'reform units', that allows you to review and reform killed units, but normally you don't receive any special information as to what units are lost.
4) Do medals improve unit capabilities or is that just Heroes that do that?
Medals do not improve capabilities as far as I know, Heroes do and don't forget experience; the number of stars a unit has give combat bonuses as well.
5) I have the Grand Campaigns but it seems like unit experience is stuck on the 1940 GC as I can't seem to get units to 4 stars, is this correct?
Yep, there is an experience limit built in for most campaigns, it's usually stated in the first briefing, together with the number of SE units you can receive.
For GC'40 the exp limit is 325.
6) Can you download new units?
Units, campaigns, graphics, there is a lot of modded content available. It depends on what you are looking for, I guess.
7) Can you name your units or give them other designations?
Yes, you can rename your units, select a unit and press Alt + N.