Thanks for mentioning possible dust issues with the RX1, no need to think about that camera any longer.
I still have my A7 that I bought from the first badge to arrive in The Netherlands in late 2013, alongside the A7R2 which is my main camera since early 2016. I use the A7 in my little studio at home, where it sits on a tripod with a bellows and various bellows lenses, ready to photograph lenses and stuff in my collection; in theory it's my backup camera though I've never needed it as such. I agree with the previous poster that the A7II's great advantage is the IBIS (in-body stabilization or Steadyshot in Sony speak), I wouldn't touch a camera without it now that I've had the pleasure of having it. I'd only recommend an A7 for use with manual-focus lenses, on a tripod or in bright sunlight; for anything else grab an A7 model from the Mark II or III series. IBIS is especially useful up to 85mm or so, for anything longer the sensor cannot make large enough swings to keep up with the lens' motion when focussing in magnified mode, the viewfinder image gets jumpy even though I have a fairly steady hand. So for telephoto I still strongly prefer stabilized lenses.
Other advantages I'd value in an A7II over the A7: tougher lens mount, better AF, better ergonomics (number and customization of buttons).
I had a Meike grip for the A7R2 and replaced it with the original Sony VG-C2EM grip so I agree with the previous poster: buy the Sony grip for a Mark II camera. I still have the Meike grip for the A7 which works OK; if I was going to use it on a regular basis, I'd also try to pick up a used Sony-branded grip. Disclaimer: I like to buy premium stuff whenever I can afford it.
I'm pretty sure that within a year or so the resale value of the A7II will make you cry almost as hard as for the original A7. Blink your eyes and your camera's value has depreciated once again. I still have a working NEX-6 (bought 5 years and 7 months ago) that is worth next to nothing but is borrowed by my daughter on each vacation because it's a "super-nice camera" (her words).
TL;DR
Sorry about the rambling. Used A7II's will be flooding the market now that the Mark III is in the stores and prices used or new will become attractive; for general use the A7II is a much better camera than the original A7.