Mr K, welcome to the forum!
The answer to 1, 2 and 3 is no, although you could create custom runway centrelines as an outline file - but it would be a lot of work.
To number 4, I don't use the standard RB airway maps in the UK, I use different outline files. However, all these outline files are produced by a file that makes up the outline using start and finish lat/lon points to draw the line, so creating dashed airway lines would be a huge job.
I don't tend to have the NOR/NDB/Fixes showing on my screen - you can switch them off or make them a colour very similar to the background colour so that they don't stand out so much.