regexp find and replace with multiple line support
Maybe in some distant future...
move open file tabs left or right or drag to organize them
Sounds like cosmetic crap, more than anything else...
right click of folder in project file list should bring up "add files to this folder" option
No. Placement in the tree is determined by file extension and/or content - the user should not mess with this...
split one file window into two or more viewing panes
The Window menu can bu used for this (an is more backwards compatible, if you don't even use the tabbed interface...)
"include files" folder on project file list should not automatically close on change
Known problem, but since it's much easier to rebuild the tree, than doing an incremental update (for all cases), it would be messy to fix - and I don't think it's a big problem...
multiple instances
Read the docs, use /x option - but the IDE is single instance for a reason...
#pragma once
I have considered it before, but since it adds very little useful, no...
BUG:
if source file path contains "(" e.g. C:\code(1)\test.c then when double clicked on the build error list it tries to open "C:\code(" not the full path
Extremely rare case - but, yeah, I guess...