A lot of guys that are heavy into networking/IT stuff, highly recommend the MikroTik stuff. It isn't for the novice as it requires a lot of actual programming. But the stuff is solid.

I would be more than curious why your 'Home Automation' guy is wanting to get away from MikroTik in your install. If he was having problems, it was likely due to programming issues. Which might indicate that level of networking is over his head - this is common for a lot of us A/V guys. But there are people he can contact to sub-out that part of the project and could get things worked out.

As far as the Araknis routers go. They are similar to many other consumer routers as far as setup goes (they are simple, not requiring a lot of network/IT knowledge in particular). You pay a bit more for them due to support, which is what you need right now.
The MoCA should NOT be having an issue, which brings me to the next point =

With what appears to be a lot of 'different' problems you have been dealing with, you NEED someone there 'physically' to look over the installation. Something is going on and you could have some bad connections, some bad components, or a mistake made in the installation of everything.
Who did the actual installation?