So I started with xulongwu4's suggestion and it now works!!! Thanks!

No it's not working.
Interesting that I discovered that rainbowstream had the same issue. But I fixed that by basically reinstalling it. I then tried reinstalling variety, but that did not work.

You were right. It didn't work.
Also, I have to wonder why python would get messed up on one computer, but not on the other.

Don't know if this helps, but:

To test my mouse, I connected the BT MS Sculpt Mouse to a different computer (a Mac). It works fine. Of course, I had to leave it be to see if it was somehow permanently disconnecting or something. But no, ater 12 hours the mouse works fine without having to reconnect it.

TLP is not installed on either computer based on your test. Both came up 0.

Well, now neither mouse remains connected to the Surface..... I do have one more BT mouse: an Apple one. I guess I'll try it at some point and see if it maintains connectivity.

Actually, I don't agree. Here's the thing. Like I said I have 2 of these mice. I was actually thinking one of them is faulty. I am no longer using the computer with the BT dongle, but 2 different computers with built-in BT. The SurfacePro3 computer worked flawlessly with the mouse. I did notice though that if I watch the BT interface for connecting BT devices, after a period the mouse will be disconnected, but as soon as I use the mouse it will connect and work fine. So they obviously disconnect (to preserver battery, I assume?).
Now on the other computer I connected the defective mouse and it was doing the same thing. Disconnecting and never reconnecting unless I forced it to. So I decided to use the "good" mouse on that computer. And it's doing the same thing. The "bad" mouse is also not reconnecting on the SurfacePro3.
One other thing I notice. If I watch the BT interface on either computer the mouse status goes to Connected, Disconnected, Connected, Disconnected, etc., so long as I'm trying to use the mouse.

Josh, I'm inclined to agree with you. And anyhow, I've decided to retire that computer. Thanks for looking into it though!

Don't know if this is of any help, but here are some bluetooth related logs:

It is a MS Sculpt Mouse (something like that). I use the same one on another Solus computer without any issues. It's just this computer. Also, I should note that whereas this computer does not have built-in bluetooth I have to use a BT dongle.
I just did the latest updates and nonetheless the mouse lost all connectivity. I did discover though if instead of deleting the device, if I put the mouse in pairing mode and then in the bluetooth settings for the mouse, just click on the "Connection" slide-button, it will reconnect.

Don't know if these logs help, but this is just before force restarting:

I think it's ok. I haven't had issues with resources behind hammered in quite a while on any computer.

Oh no. It's been stable for a long time! Thanks!

Another interesting fact seems to be that Variety on a Surface Pro 3 has not been leaking. It's working fine.
The computer is was leaking on btw is a Lenovo U310.

Yesterday, May 4, 2017, did a new install. It's much more stable, but will occasionally hang. I'll note also that Variety isn't leaking on this computer although it does on my other one, which I've reported and will cross report now.

I've upgraded the Surface Pro 3 to unstable, but no difference.

Ok, this is interesting. With the latest update (post April 17) now memory maxes out, while swap stays low. Again, I've tested it and it happens only when Variety is left on.

Don't know if this is of any help. In order to further track down the possible culprit I launched Evolution (which is guaranteed to stress the system) and then moved to a terminal session (Ctrl+Alt+F1) and I see a lot of errors related to:

I got a theory about this. I loaded glances on the SP3 and watched it while running apps I know are likely to cause the computer to lock up. So far it seems that if the context switches indicator (ctx_sw) is running in the red (>18000) for an extended time (just a minute or 2), then it will lock. The load, cpu, memory are all fine.

Oh another thing, You can't boot without the keyboard.

Just reinstalled Solus on the SP3 and again after a few minutes it will hang. Now on each occasion this time Evolution was working. So I'll try without Evolution and see if it hangs. But again, resources are being stressed and I think that causes it to hang.

Sorry... As I recall the errors occurred after issuing the command:
sudo dnscrypt-proxy /usr/local/etc/dns...conf (i forget the exact conf file name);

Ok, I'm pretty sure this is somehow the fault of the program - Variety. For most of the last week I never had Variety running and never had this "swap" issue crop up. But no sooner than I launched Variety within 24 hours the computer was slammed again.

I can add that I recently used my computer on another network and I forgot about this issue and was confused as to why things were not working, then remembered... ah, I have to reconnect again and then it'll be stable.

However, in T1406 he's obviously having continuous issues. Mine is just 5-10 minutes (today) after a boot. I went into journalctl, but there was nothing about why connectivity might have been dropped. This is the first linux system I've used where things are logged to journalctl and not in separate log files. So perhaps there's somewhere else I should be looking or I need to change what is being logged?

OK, for whatever reason, today it started on it's on, so I guess you can forget it. We'll see how consistent it is across reboots.

For Nylas it was some libxwww, something like that.