Hi RichardJ,
on welcome to track editing
I will try to answer your questions point by point this time as it's your first time with GP4 Builder / GP4 track editing:
>>it overlaps the starting section slightly
That's normal, if you check an original GP4 file, you will see all the tracks have their latest section that is overlapping very first one. In general, when you wonder is something might be done a specific way, check an original track and you will get the solution.
>>The major problem is it is offset to the left about half the track width
I assume you built all your .dat track and that at end, beginning and final lanes are not aligned, that's a usual case. It's due to some imprecisions in the way you built track and thus at the end, a little degree more in that curb, a little meter more longuer this straigth and you end with half a track width offset...
You can't do much than deleting last sectors (usualy last curve and last straight) and rebuild it by test and trial up to the best alignement you can do.
As GP4 sectors are no more sections (groups of sectors) as in GP3, you can't edit any curve back in the track and have all the end of the track that line up with your changes (in fact, it's in the todo list but it needs some work on my side and proabably to create a new file format specific to GP4 Builder, to save your changes, but it's definitely a work that needs some studies).
So if you need to change a curve anywhere in the track, you will also need to rebuild the whole end of the track, I'm sorry.
Anyway, I'm sure you noted you can create multiple sectors at once to create perfect curves or straights.
>>Also on first track section (initial/section 0) the area to the left of the first section of track the area does not line up with the space between the track edge and the rail.
Hmm, i don't get what you mean exactly here, can you show any screenshot to illustrate this ?