doing "all" the things your doing may be confusing to the dog,,
But I see your reasoning in trying them
This is what I do, and it HAS been working as Masi can be a puller when the mood suits her..
I do this 20 minutes EVERY day (masi is 10mths old by the way)(per my new trainer)
,,you may end up 'dizzy' from this,,but it does work in the end..
Start out with no distractions,,6ft leash, and I have Masi on a mini prong
) holding only the 'loop' of the leash,,no talking at all, start walking like your on a mission
),,if she pulls (since this is what yours is doing),,the minute she is ahead of you, change directions,,KEEP changing directions if she forges, and absolutely NO TALKING,,(dogs tend to not like being ignored, the eventual premise is,she is gonna wonder what the heck your doing?LOL)
If she lags, pick up the pace,,it's imperative that you keep changing directions when she gets ahead of you, do this for 20 minutes straight, at the end, whether she's been good or bad,,stop the exercise and praise her
I worked on this for a week daily, with masi, and it mentally, as well as somewhat physically wore her (AND ME!) out,,but got her up atleast next to me and not pulling..
I've found if we are not consistent with one method,,throwing in a bunch of different ones confuse the dog..may take a few times to find a way that does work whether it's clicker, flat collar, whatever,(which it sounds like you've tried em all
Masi is no good right now on a flat buckle,,and believe me, I've tried a few different ways and it just wasn't working,,now that she's 70+ lbs,,I need better control and this way seems to work for her and me at the moment..