For correcting the blurry picture, the following applies for my Panasonic VT60. It’s a bit of a pain, but will give the highest quality output. Much cleaner and sharper than generic modes at least.
1) Set output mode to Lx3/4
2) Set linemulti output mode to optim 320×240
3) Go to sampling options
4) Scroll down to 320×240 optim
5) Might need to use Harrumph’s trick to get an image to appear on screen. Involves increasing V.active to 256, then reducing V.backporch until you get a stable image. Firmware 0.76 required a setting of 6, 0.77 requires a setting of 2 or 3.
6) Now you can play around with H.samplerate to try and get the graphics looking all a smooth and crisp. Basically, just keep incrementing H.samplerate by 1 until everything becomes sharp. As examples, Sega Saturn 320 mode games require a bump up to 427 or 428. Non-320 modes require a setting of 455. Panzer Dragoon 1 is an example, capcom fighters also.
7) If you used step 5 to obtain a picture, final step is to restore correct AR. Do this by reducing V.active back down to 240.
My understanding is that the H.samplerate adjustments are not compatible with all displays.