Well, I don't use the ASS format myself. I have written the SRTtoASS3D function for a specific user, and also because it was a nice challenge to convert simple SRT files to ASS with the correct 3D depths.
OK for point 1. It is easy to implement the modification yourself (in case you are in a hurry). Just edit line 1147 of SRTtoASS3D.tcl and change it from
set restorecolor "{\\c&H[SrtColorToAssCode $color]&}" to
set restorecolor "{\\c}"
Indeed, it's a simpler syntax. I did not know it, as I have simply analysed a couple of ASS files to understand the syntax, but I have never studied that format.
I will try to fix the problem described in point 2, although I have never seen a SRT file with a font change (other than its color, and even that is extremely rare). I agree that the color change in a SRT may be missed if it follows a font name change, but it's so rarely the case that I don't think it's really a problem. After all, almost all SRT files have no formatting at all, and when they have some kind of formatting, it's usually limited to italics. But I will do it anyway.
I'm not sure I can easily change the font name. Not because writing the code is difficult, but because usually the font type or name is not specified at all in the original SRT, and above all because if it is specified, I cannot be sure that the same font exists in the computer, TV or player that will be used to play the final MKV. Can I simply copy the font name from the SRT and insert it in the ASS, with the risk of specifying a font that the player can't use? Perhaps the player may even crash.
Also, I don't understand why I should implement the font name change, but not the font size. Is it because the SRT format doesn't permit to change the font size? And anyway, the font size is dependent of the font, and the user should select the right size according to the "XML guide file" and the font he has selected in the GUI (as you can see when you use the Analyse the subtitle guide option). If the font (name or size) changes in the middle of the stream and if the resulting subtitle is too large, the 3D depth may not be suitable any more, because the subtitle may enter into the objects in the foreground. Don't forget that this tool converts the SRT to 3D, not simply to ASS, and that introduces some difficulties. So, to reply to your question, I'm not sure I will implement the font changes, but I will certainly fix the possible bug with the font color.
SRTtoASS3D.tcl is written in
Tcl/Tk.
TCL is the main programming language, and TK the ToolKit that has motivated me to use that language to code most parts of BD3D2MK3D. It's an interpreted language, somewhat slow, but TK is very powerful to build complex GUIs, and since BD3D2MK3D is essentially a GUI, IMO Tcl/Tk was a good choice.
I agree that the warnings about the color depth or the Full stereoscopy should not be displayed each time BD3D2MK3D starts, but I can't change the dialog to add the option to not show it any more, because it's a standard system dialog that cannot be modified. I will try to disable the warnings when BD3D2MK3D starts, but that will not be an option. You will still see it if you manually change these options again.
BTW, you wrote "BD3D2MK3D opens to the last saved state". That's only partially true. You can change that by disabling the "Save tabs settings on exit" option, and BD3D2MK3D will be opened each time with the settings you have saved explicitly with "Save tabs settings now". (The options available in the menus are saved immediately anyway.)