The energy efficient shed project is coming along well and now I’m working on the trim and furring strips before installing siding.  I have a few questions.

1) How far from the end of a run of siding can the furring strip be located?
For example, do I need furring strips that butt up against the edges of the doors and against the corners so I can put a nail in the last inch of each piece of siding or is it OK if the nearest strip is a few inches away?

2) There are some really tricky details involved in wrapping the corners at the bird box and integrating into the frieze board (with the ventilation gap underneath) at that specific location.  I need to do some carpentry tricks and I don’t want to use the hardie trim because I don’t think it will be strong enough and it’s a bit annoying to work with (e.g. I need a piece that is 6″*3/4″*1″ to fill a gap).  I assume I can use any wood for the purpose and paint it to match?

3) I am using the 8 1/4″ lap siding boards.  I can cover the wall with 13 boards with the minimum overlap but I have enough material to go to 14 boards if I increase the overlap (decrease the reveal.)  I’d like to adjust the reveal to match what is on my house if I can.  Is there any downside to increasing the overlap?  I could find a minimum overlap in the specs but nothing about a maximum overlap.