UPDATE
Everything is working. On a whim, I added my FARM account to the domain admin group for the provisioning process. Then I rebooted. Everything has started, the sync service in Central Admin AND the two FIM services.
Now, that SHOULDN'T have been required. But, it worked.
Anyway, things are working fine now.
If you end up doing this, don't forget to REMOVE your FARM account from the domain admin and local admin groups you have added it to.
Additionally, if you have this much trouble, it is recommended that you wipe everything and start fresh. A lot happens with the UPS service during provisioning and its better to have a clean system than a dirty functioning one.
SOLUTION (END)
These errors are related to UPS provisioning incorrectly. This is likely related to issues with the existing active directory in the environment, e.g. not being able to read appropriate AD objects, the network path not found is actually related to this. The UPS is a beast. If you run into these errors and have exhausted EVERY recommended avenue, assess your active directory. Check its functional level, policies, standard permissions etc. For example, we found in this implementation that initially, some user accounts did not have basic read permissions. Then, start over, cleanly.
Best Answer
The various levels will each take the load their supposed to process, but if you have multiple (eg, multiple web servers) you will need to use a hardware load balancer, or MS's built-in NLB feature (or possibly a 3rd party software).
Edit:
To install MS NLB, follow MS's instructions here. Then configure SharePoint for it. Instructions for WFE servers here. Depending on the versions your using, the process might be slightly different. Those should get you pointed in the right direction at least. There's also quite a bit available by Googling "SharePoint NLB [service]" where [service] is the part of SharePoint that you're trying to load balance.