I recommend that you install GNS3 and download a copy of the CHR (cloud hosted router) virtual image from Mikrotik, and do some playing around with routing in GNS3 because a forum thread isn't an ideal place to tell you how to do routing if you've never used OSPF before.
Get started by building some basic networks, such as you'll find on the Wiki:
OSPF will give you the ability to fully control the packet flow in your network, but switching from a bridged network to a routed network isn't just a flip of a switch. It will take some design work and some planning as to how you're going to do things, but if you set up a lab in GNS3 to play with, you should be able to learn what you're doing without worrying about breaking anything.
Basic tips - avoid using "redistribute connected" as your default way to put local interfaces into the OSPF routing table. Create a network statement instead because redistributed networks are 'second class citizens' in the OSPF table.
Make the default interface type in OSPF set to passive=yes, and then any interface where you actually want OSPF to talk to another router, create that interface manually and set passive=no.
Configure the default cost to something like 100 so that you can adjust routing in a smoother fashion later.
If you do redistribute static routes, try using some filters that allow you to easily create "private static routes" that won't go into global ospf unless you want them to.
Assign your IP addresses to POPs in contiguous blocks on CIDR boundaries:
i.e. 192.168.32-64.x is routable as a single block: 192.168.32.0/27 but 192.168.10-20.x is NOT routable as a single block.
Meanwhile, your initial question about RSTP - if you use a CCR router to do RSTP, then you'll want to look at the performance tables under "routing" - yes, I know it will be bridging, but make sure it can handle routing or bridging at your anticipated traffic rates. If it can handle both, then you can create a bridge in the CCR and bridge the fiber and wireless interfaces together and use RSTP to block the wireless interface while the fiber is operational. Just go into the bridge configuration, edit the bridge and in the STP tab, set Protocol Mode to rstp.
While you're at it, make sure to go into /Bridge > Ports and check the cost values of the wireless interfaces - you want these to have a much higher value than the fiber interfaces so that they're definitely going to be seen as inferior to the fiber interfaces.