Water is draining slowly and also backing up into other drains (water drained from washer backed up into toilet). There is also a leak in the main water drain now as well. Could these all be related or are they multipl different problems?

Could these all be related
Yes. Sounds like partially blocked sewer line. Pull toilet and snake drain.

You could also look for a cean out on the main but tell me if you find one before opening it. You can also snake down the vent stack on your roof if it safe to get up there