First off, thanks so much for really complete details! It helps a lot to know so much about your situation (and makes me, at least, more willing to have a look ...).

So you have a 46 oz tent, and are considering replacement. Obviously you want to save more than just a couple of ounces, or it's not worth the money and hassle, right?

Further, you don't use trekking poles, so you would need a carbon fiber pole (or poles) instead if you got a tent that used one or two separate pole(s). Figure about 2 oz per pole depending on length, added to the weight of the tent. Making it more complicated is whether your existing tent weight includes stakes or ground cloth; I'll assume neither.

Given your price point, I would stay away from Zpacks. Mountain Laurel Designs sells their Cricket tent is $315, but I suspect that particular design will work better with for a person that uses two adjustable trekking poles.

You might consider a couple of offerings by Six Moon Designs. For example, their Lunar Solo is 24 oz at $215, add 2 oz and $30 for a carbon fiber pole. If you're not too tall (torso not long in particular) and you can sit up in it comfortably, I like the design of their Skyscape Trekker better, same weight $20 more expensive. BUT --- it requires two such poles. No problem for someone using trekking poles, but for you that adds weight. I'd consider the Lunar Solo. http://sixmoondesigns.com/tents/LunarSolo.html

Someone already mentioned tarptent.com, and in particular the Moment. Unfortunately it's only 10 oz lighter than your current tent. That's something, but ...
I would ordinarily be more inclined towards their Notch or ProTrail tents, but both require a couple of poles, jacking the weight and cost up for you.

Overall if it were me I'd be looking at the Lunar Solo. This tent has been around basically forever, so you might well find a used one somewhere (or other options used of course). BackpackingLight has a for-sale forum, though you might need to be a member (?).
Whiteblaze.net has forums for things requested to buy and for things to sell.
And of course, this site does too.

Given your other requirements, my suggestion is that you give up on the freestanding issue. My personal experience is that I can always find someway to put up a non-freestanding tent. Sometimes it gets a little tricky, but the vast majority of times it's no problem.