Been wondering 

I recently leveled to 81 and 74 I recieved 1/2 medals. I am not upgrading most infantry and cavalry units beyond level 5, because I believe that I would run out of medals. 

But seeing that We receive medals after levelling up, I assume that won't be possible, especially because new 25 levels are added every 8 month. 

So is it a good idea to advice people not to upgrade knights and pikes beond level 5. Or is there a level when you stop receiving medals?

So far I know several players over level 100 that are still getting 2 medals for each level. That still means you will probably have to spend sapphires for medals after a certain point so yes, I would only use medals for Occult and Beastiary.

Hello.

You receive Level up points for every level up.

There is no Level when you stop receiving them.