Actually almost any car, CUV, or SUV with 5" or more ground clearance can handle gravel roads as long as you don't have to navigate major ruts, potholes,. mud/clay/deep sand, nor snow over 2-3". Under those circumstances, no mods should be needed.
I live along the I-5 corridor in W WA where snow is real hit and miss. Some years none, occasionally enought to paralyse traffic (that's anything over 3" here!). When that happens lots of services and business shut down and people just stay home for a day or two till it melts. Lots of AWD rigs here, but definitely not required.
To directly answer your questions:
The RAV 4 is certainly competent for gravel roads & would likely prove quite reliable. IMO your best bet in your price range.
The Escape is a decent vehicle. CR rates the 2012, 2016, 2016, & 2018 as having good reliablity. They ding Escapes for fuel economy for the eco-boost engines, poor overlap crash tests, and somewhat cramped seating. We had a 2004 Mazda Tribute (Escape twin) for 3 years & 30K that was trouble free.
A Honda CRV, Kia Sportage Hyundai Tuscon would also fill the bill
As a 3 time Subaru owner (2004, 2010, & 2015) I wouldn't hesitate to get one of those either. A few Subies have oil consumption & wheel bearing issues, but many go 100K plus without significant problems and total breakdowns are rare. IF they were unreliable they would not be the number 1 car in WA nor have such a high resale value!
Ideally, if your budget permits, I'd try to get a 2015 or later model to get some of the improved safety features that benefit all drivers.
RX300 is certainly a great vehicle tending to be upscale compared to the above. But to get one in your price range will probably mean a model before modern safety nannies were part of the package.