(I) LilyPond export in Musescore 2 / (II) Palette font size / (III) Synthiziser / (IV) Opening older mscz-files

(I) Sorry for asking now, since you already arrived the RC status of Musescore 2.
I recognized this quite in the initial stage, but always thought there will be enough users missing this feature. As I can see now, I was wrong with this assumption.
I know there exits xml-export and you can import xml-files into LilyPond/Frescobaldi. But sometimes the with Musescore generated xml-files are somehow corrupt and couldn't be imported into Frescobaldi (I don't have an example file right at my fingertips now, but I will deliver one, when this error will occur next time). In these cases I always had to use the lilypond-export (of course I used it as well in other cases, but in those cases I was forced to).
Perhaps the LilyPond export is not perfect, but it worked, when xml did not work.
I understand, that you did not program Musescore as a foreman for LilyPond/Frescobaldi and layout options are really better in Musescore 2, but it's still a lot of manual work compared to LilyPond (which is the reason, why I use it very often for the finishing). I can imagine, that it is hopeless at the current stage of development to enable/implement LilyPond export again, but maybe, maybe you will think of it in the future again.

(II) This request is late as well: The palette font size or rather the general font size was customizable in 1.3., but isn't in version 2. This is quite awkward with really high monitor resolutions (e.g. 2560x1440 and more). I'm truly not blind, but every user is getting older and in most cases even blinder. Also monitors with higher resolutions are getting more common and scaling of the user interface is very different in quality from operating system to operating system.

[ Ok, this point seems to be fixed in RC
(III) By default the synthesizer is over-modulating using wind instruments (especially brass instruments). So every time you have to open it and change the volume (a value about 20 seems to be OK). Setting this as default (in the synthesizer dialogue) does not change/save this adjustment. So you have to do this every time anew, otherwise you will get this overmodulation/blasting(?)-effect.]

(IV) When opening in RC older mscz files (but it also happened with xml files) you get an error message "Load Error", "File corrupted C:\...". So, when pressing "Ignore" the file will be loaded and seems to be OK. But why are those files suddenly corrupted? Opening the same file with an old nightly build (aa3d4df) didn't show up the message.

PS
Shouldn't the icon design for Musescore be consistent irrespective of the operating system? In OS X it's round, in Windows (and Linux?) squarish. I would prefer the round version aesthetically and in order to better distinguish between the old and the new version (for people using both versions, because of this brilliant LilyPond export ;o)
PPS I'm no fan of this tendency to "monochrome" all symbols in tool bars as it is done now. Color is besides the shape a further (important) distinctive feature and makes it therefore easier to find the right symbol at a glance. Perhaps you reconsider this in upcoming versions of Musescore. It's also imaginable to implement an option to change the style of symbols like in Libre/Open Office. (I know this is impractical for documenting Musescore, but there could be a hint right at the first chapter of the handbook, that all illustration refer to the default style etc. Also this doesen't seem to be a problem in Libre Office Documentation)