You may want to consider loading v7.2rc7 in the testing channel. It has a lot of fixes (but possibly some new bugs), but for sure it has bridge related fixes.
Also, your RB5009 has many ports available. I would use some of them as access ports for some of the other vlans, just to limit the amount of other equipment that is involved. Once you get things working on just the RB5009 ports, then start branching out. Crawl before you walk, walk before you run. You can troubleshoot a lot of access issues just by working with the ports on the RB5009, then once you have things working there, when you add a switch, if something doesn’t work, you will know it is related to the connection to the switch, or the switch configuration.
Partiioning the problem into manageable pieces is very helpful when troubleshooting. But even then some issues can be frustratingly hard to troubleshoot. For example this thread.