I would like my partner to test out my game as I progress with it, but I was wondering if there is a way for them to do so without downloading Quest?

We tried loading it in a browser but I guess we didn't read how to do that properly, as it just repeated a link to download the same game they just dragged into the browser :P

I was phobic of uploading, but I see now that there are optins to tag as Work in Progress, etc. I can just do that and link them.

I think the short answer about running this without downloading Quest is... no.
(Unless you play online, which (I think) uses this site's online quest program.)

Yes. Just publish a test version and check if the is running ok online. If so, your friends can check your progress from times to times online. Remember when you are done with the test step, publish it in a separate folder. The published version is what you upload. Everytime you have a new version, hit the publish buttom, overwrite the previous version and use the webpage to update the game.

Updates are not done like the first time. Use the game listing link and then the edit button to update a new version of the game.

A standalone option/version which doesnt require the site i'd happily pay for. I love the editor and the tools as I'm no coder but being constrained to software/site doesnt thrill me.