Jeans Technicos/Techniques - Further Disasters in Flat-Felled Seaming!

Jeans techniques are challenging my sewing skills, however I've also get just a few other...  sewing projects going. I refit B5526, got another shirt partially cut out of it, and began working on fitting a new (to me) tee shirt, the Hot Patterns Weekend Sunshine Top .

It's multi-tasking like this, that keeps me enchanted by sewing!
~ ~ ~ 

Oh dear, my journey into the land of the flat-felled is not following a smooth - or straight - road
Woof! Look at that topstitching line!!!! You can practically hear the sound effects 
as the needle moves back and forth, right?
Believe it or not, I was focusing
on the toe of my presser foot lining up as I sewed,
but it looks like I need to find better visual  guidelines.

This light-weight denim moves around
Did I actually trim one edge too close?

A few posts back I shared my challenges when it came to sample sewing flat felled seams in a light/medium weight denim . I gave it another shot tonight, this time using both a heavy levi-type weight (the pale/washed out blue sample above) and some of the light/medium weight (that indigo blue with the scrolly rose design over on the right). I thought if I skipped the glue stick I used last time, to hold the tucked under seam in place, I might avoid the needle-jamming problem I had before. I also thought that if I simply sewed a wider gap between the original seam and the topstitched one, I could get a nice straight seam line and avoid the problem of the raw edge not being caught in the top stitching and peeking out.

Hummmm...

1) It does appear that the glue stick was the culprit in the jamming. I have certainly used glue sticks successfully in the past for a variety of projects, as have many other sewists, but perhaps when working with heavy weight fabric, or maybe it's the heavy denim needle, that may not be a good idea. So, one problem solved, it didn't jam.

2) I'm not, however, making progress on the straight-line front. My topstiching was, if anything, even more crooked!

3) In addition I continued to have problems with a raw edge of fabric poking out from under my flat felled topstitching. I can't seem to get the longer edge to fit in underneath the trimmed seam. Am I trimming it too close to the seam? I wonder if that is causing this problem.

Next....

a) I'm going to focus on this flat-felled seam tutorial from Oliver + S, and see if I get any new ideas about what is proving to be surprisingly challenging for me.
b) I wonder if I should go for a wider seam allowance. I've been sewing a 5/8 " seam, typical for wovens, and trimming one seam down to about 1/8". Should I cut a 1" allowance and then trim the one seam down to.... maybe something closer to 1/4"? I might try the 1" seam on two different samples - one with a 1/4" trimmed seam and the other with the 1/8 - or at least very closely trimmed seam edge.

But first I'm going to read more about what others have to say about this type of seaming. In addition to the Oliver + S article, I'm going to look through the Pattern Review article "Make your own Jeans, You Can Do It"  and also in my all-purpose Readers Digest sewing book.

Can you imagine how much more enchanted I'm going to be with sewing, on the day when I've resolved these challenges?