6.41.3 Can you answer these questions?

6.41.3.1 Lua function that replaces strings, but ignores spaces and TeX comments

https://tex.stackexchange.com/landing/r/digest?cta=question&id=557091

I would like a Lua function for LuaTeX, called 
replaceButIgnoreSpacesAndComments (<string>, <what to replace>, <what to replace it by>) 
It is supposed to work like a string  ... 
[luatex] [strings] [lua]
 

asked by Gaussler https://tex.stackexchange.com/landing/r/digest?cta=user&id=19809 1 vote

6.41.3.2 Lettrine loversize causes Parallel text to be bottom aligned

https://tex.stackexchange.com/landing/r/digest?cta=question&id=556979

For some reason, using a lettrine with the optional loversize argument at the start of a ParallelLText or ParallelRText in a p-type Parallel environment causes the parallel text to be bottom-aligned  ... 
[xetex] [lettrine] [parallel]
                                                                                  

                                                                                  
 

asked by Andrew Ray https://tex.stackexchange.com/landing/r/digest?cta=user&id=212888 1 vote

6.41.3.3 Incompatibility between LuaLatex font feature and Graphite?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=555419

when I use LuaLaTeX to modify my font (for example here kerning) at the same time as Graphite, there seems to be a problem because nothing happens. Everything seems to go well when I'm not using  ... 
[fonts] [luatex] [fontspec] [directlua]
 

asked by Bastien https://tex.stackexchange.com/landing/r/digest?cta=user&id=209957 1 vote