Will this amp trick work for increasing bass performance?

Yes, provided you have 'high level input' connection on your subs. Most higher quality subs have two ways you can connect. Either 'low level' RCA connection from your pre-amp (passive) OR you can run a short set of wire directly from the back of your speaker connection to the 'high level' input on the sub woofer. 

Super easy to do provided you have 'high level' inputs.

The reason I ask about Tidal is that some people connect from the TV app. This method gives you low resolution and very reduced dynamics.
Your connection seems to be fine.

Don't know the best way to connect an equalizer to the Ayre.  Address the question to the manufacturer.

I am not bi-amping.
I am going from the amps to my speakers via a high-wire configuration, dual wiring on the speaker side.
If you are concerned about having enough power, remember xa60.8's are class A to 60w then convert. Class A is much more efficent. My strategy in Class A and Tube Pre was to drive the purest most musical combination I could design. Maybe consider bi-amping as a second option if you feel your speakers are not being driven. In my case, I don't  believe it will be necessary. 
Again Kent at Pass was an excellent resource. I believe I spoke to him three times before making my purchase. The EVO's are sensitive, any of the Pass amps you are considering should drive them.

I also have a large room, and my solution was to triamp with an SS amplifier for the 2 subs (LP @ 48hz 24db/oct) Magneplanar MG 20 bass panels on another SS amp (LP @ 220 Hz 6db/oct, no HP filter), and a third amp (Tube) serving the Midrange/tweeters (HP @ 290 Hz 6db/oct, no LP filter). The crossovers are Pass Labs XVR1s. This stereo is way out there for a system, but it really sings! I have made incremental changes, one at a time! to arrive at its present incarnation.
You really need to experiment with the speaker locations to get the best compromise between imaging and bass response. I am pretty sure you will need to have a stereo pair of subs to get the bass right for audio and audio imaging. Two subs will allow more flexibility in the room setup, and some of them are pretty small, which will help the "cosmetics" of the room. (WAF). I have read good things about JL Audio and SVS for subs. JL Audio has a couple of in wall subs that can be completely unobtrusive.
Good luck, this sounds like a really cool project!