For me, "hold on to" and "Keep" in this particular sentence mean the same thing. "Hold on to" can mean "to keep" or "to not let go of" -An example is when someone tells you to "hold on to" the person you love, meaning "don't let that person go away," or "make sure to keep that person by your side." -In the context of "to not let go of", for example, someone may be about to fall from a cliff and is hanging by just one of his hands. Then someone else throws a rope and tells him/her: "hold on to the rope." This means "to grab the rope and to not let go of it" because they might fall. -Another example could be the sentence, "hold on to hope." When someone is loosing hope about something, and he/she is told "to not let go of hope." I hope these examples are helpful to you.

Yes, you have the right idea. So in "hold onto it" we mean the same thing as "keep it". Say you are at a movie and you need to use the bathroom, you need your ticket to get back into the movie after you've gone to the bathroom. So in this case, I would say "hold on to your ticket, you'll need it later", or "hang on to your ticket, you'll need it later" (same meaning).

"Hold on to the ticket" and "keep the ticket" have the same meaning. You can also say "keep hold of the ticket".

Same. No Difference. . Also can be used somewhat more literally. Hold on to your hat, we are in for a bumby ride. Can be used figuratively for non-rides. :) . Hold on to your dreams. (Keep believing)

OK, I really appreciate your help!