First rule: Gathering opinions is okay, but never buy without first listening for yourself. Someone else's idea of audio nirvana could be your idea of hell and vice versa.
Second, you're duplicating up with two sets of front speakers unnecessarily.
With a little lateral thinking it's entirely possible to have a dedicated 2ch Hi-Fi, and then integrate AV without wrecking the stereo performance. You need an AV receiver with pre-outs. The SR5009 has pre-outs.
How it works is that the AV receiver no longer powers the front L&R speakers. That becomes the job of the PM5005. For Hi-Fi use you leave the AV receiver switched off and just run the PM5005 with the stereo speakers and your pure stereo sources. It's a pure 2ch Hi-Fi; simple as that.
For AV use then both the receiver and the PM5005 have to be on. The AV receiver has pre-outs. They're usually used for connecting a 5ch or 7ch power amp. However, there's nothing to say that you can't have a 2ch power amp just for the front L&R. That's what the PM5005 becomes. So the AV receiver Fr L&R pre-outs connect to a line input on the PM5005.
The trick then is to set the PM5005 volume to a point where it mimics the level that would have come from the receiver's own L&R speaker sockets. A smart phone running a dB meter app will do for the initial set-up. Record the test tone levels from the receiver while the speakers are still connected to it. Run the same test with the receiver volume display set to the same level, but this time with the PM5005 connected and powering the fronts. Once you have the volume dial on the A19 set to the correct position then mark the dial so it's possible to repeat this setting again and again. Then run the receivers AV setup routine to fine tune.
All that's really changed from the receiver's point of view is that it no longer has to supply current to the front L&R. There'll be a very small improvement in power delivery to the centre and surrounds as a result.
If you set-up as outlined above then all you need is a pair of MR4, the centre and surrounds. You save the cost of one pair of MR2 and stands. If it was me, I'd use the money saved and not buy the BR2 for surrounds at all. I'd get a pair of BXFX or look for a used set or the previous BRFX. These are dipole/bipole surrounds. They work far more convincingly, especially with movie sound tracks and where the listener to each side speaker distance is less than 15ft.
I'd also take a good listen to the SR5009 in Pure Direct mode with the CD player connected via decent interconnects (Chord Crimson or similar) versus digital coax. Pick which you think sounds the best, then demo that against the CD player in to the stereo amp.
This next bit might sound a bit anal, but it is really important. You need some objective way to measure the volume in each mode to ensure that one isn't louder than the others. Louder is often mistaken for better. So you're looking to level the playing field so that it's the difference in quality rather than quantity you hear. If you have a smart phone then a sound meter app will do the trick. Many include a display that gives both peak and average volume. Play a short clip on repeat and note the value or position of the volume dial.
You might find that coax appears to work best with the receiver and give the biggest sound (i.e. widest sound stage) but not necessarily the most cohesive sound. The stereo amp might not sound as big, but could offer more insight and a greater ability to separate individual instruments while at the same time showing you how the musicians are playing together. But if you find you can't separate the receiver from the amp then you'll know that the speakers are possibly the limiting factor.
