Hi, simple& interesting project!
I'll be happy to successfully realize it.
Based upon my experience this can be done via a direct U.I extension.
For this first step I need to have a detailed explanation of what has to be exactly modified ( e.g. what is the keys sequence substitution).
'click and drop line sizes as fixed settings' can be explained with screenshots & comments ? Yeah, the job is done!
Usually we make O.S. extensions based on A.I. with fully transparent technique and 100% installation free ... Maybe this is the right way!
Do You agree ?
If You really mean to make more changes give me a chance to do it the right way! You will be surprised of the clean & nice interface we develop in order extend EVERY software with YOUR personal add on :-)
We don't need much time for developing this: Your proposal is clear, we need only to meet specific design analysis and the work is done.
(for the bigger job) we only need to fix the good milestones to have speed in the development of the first working sample and consequently for the definitive software in few time.
Don't hesitate to contact me for questions or more detailed info
Cheers
Gianni
P.S. sorry for the english, I am not a linguist
(I am an italian expert in A.I. & network programming)