file-transferiphonephotoswindows
Windows 7 user here, though access to a Mac (in case that'd be the only way to do this) wouldn't be impossible.
I know I could download iTunes and sync all the photos, but I have nearly 4000 of them and I'd only consider that a last-resort option. What would be simply perfect: Can I just browse them in Windows Explorer on my iPhone? If not Windows Explorer, some App. If I could even get a list of Albums part of my dreams would come true.
You could use a 3rd-party app such as the free WiFi Photo Transfer to access all those pictures on your MacBook Air. It uses a web browser to access the photos, so you don't have to install any software on the MacBook Air or deal with syncing.
The whole process is easy:
Another benefit is that none of the pictures are sent to the Internet.
The easiest way to get photos from a PC to an iOS device would be backing up certain photos to a cloud service like Google Photos or Dropbox. There is no way to get photos from PC into the iOS Camera Roll that I am aware of. Check out Google Photos. It would be the most seamless solution.
Best Answer
Windows 7 should see your connected iPhone as a Photo Camera. Just use the same software that you'd use for importing individual photos from a regular USB-connected camera. Also make sure to have your phone "trust" your computer by turning on the phone and selecting "trust" from the pop-up.
On OS X, you can use the built-in Image Capture utility (or iPhoto or Aperture if you have those).