I'm new to beekeeping, and googled "online beekeeping course," and ended up at this site. They have a seven or eight lesson email course-free. Lots of good info, not really a course, just a series of emails that you read at your leisure. One of them address feeding and overfeeding. I'm not going to quote anything from there, as, the internet is full of opinions. Will let the experienced folks address your question.

I tried to get directly to the course, but couldn't do it through the "front door." Perhaps you should just google as I did and it'll get you in if you're interested.

Be well,

Ev

Here is a link that might be useful: Ploughshare Institute

I am not a bee keeper of the honey bee just the gentle mason bee. But with mason bees if you have a bee that emerges earlier than your surrounding are ready for such as no spring flowers. then you leave out the feeder for a while just until you see the flowers and such in full swing. then you cut them off so they work to get pollen and not getting to lazy.

Here is a link that might be useful: TheItalian Garden

It depend on the honey store, lift up your box from one side and if it feels heavy then nothing to worry about. On a warm day I would do a inspection and you might want to put a couple of honey frames, which are on the outside, ..move them them in a little.
Generally, you can feed all you want until you super up, which means, girls have stocked the brood boxes with sugar honey,..then all they do is, bring the real thing up into honey super and you'll be harvesting more honey.
ONLY do this if you're greedy for honey.
Personally, I hardly ever feed in spring, I want them to have good honey in the brood box as well, better food for them!