The money tree seeds are just the "unknown special" seeds you find (if you're lucky to have it grow into one, that is). Your money tree, if you care for it well, will eventually drop a money tree seed on the ground nearby where you have it planted, so keep an eye out for that.
I had 6 money trees going on my last lot and they never died, while other things around them did. I talked to them every day and fertilized every time the option was there. As you plant more of those trees, you'll harvest enough bags each day to never work again.
Unfortunately, I moved to a larger lot to expand my gardening, and couldn't take the trees with me, but I plan on going to the vacant lot and harvest them LOL. I waited until I had a couple of seeds drop from the trees before I moved so that I could start another grove.
Now, regarding cheese and eggs... I completed the opportunity that said I was able to grow these things but when I try to plant cheese I have no option to do so. I'm worried that I recieved recipes for these two, which I didn't read, then I moved and they are not in my personal inventory any longer. Anyone know if this opportunity did in fact offer the recipe books? If so I'll have to quit my chef job and start it again to get that opportunity again?