Note he wasn't using his main but this just one set.
You are at a pretty decent level when it comes to pressure. You seem unsure of yourself though when you hit people. Commit to combos and max your damage or commit to resets. For now I would say use your meter only on LK mb and clashes. You burn a lot of meter on mb F/B3 and lightning charges to try to get in. You gotta train yourself on getting in without those tools. Later on to dominate people you need to be able to destroy people meterless. If you aren't getting hit and you do the hitting you wont have much meter.
Use sonic pound
@
Zyphox opened my eyes to using sonic pounds a long time ago and I still use it. It is a great non meter ender that lets you play oki mind games with your opponent.
Strategy
First hit always go to mb trait combo. You get first hits a lot but dont conver to 50% combos that hurts a lot.
2nd bar force clashes and go for traitless damage. Until you get really good at mindgames and resets you shouldn't avoid clashes for now. Flash has no projectiles or ways to avoid clashes and do damage so just get it over with. If you conserve your meter from my first advice you should almost always be equal or > in meter. After they clash trait up or trait combo for solid easy wins.
RMS
Use running man stance more and be comfortable with it. It is necessary to fight characters that out pace you or out footsie you.
You have a natural offense that is strong already, I dont have to give you much advice on your mix ups but you want to convert to harder hits and practice combos.
Most useful and standard combos are
starter > mb kick >11>b22f3 >ender
Air 2 Air J1
It is very good to use against anyone in the air and leads to devastating damage for no meter.
Lots char specific stuff. I really should try to do a Flash Community guid at some point to break down matchup knowledge more. Sorry everyone I barely get much to play so I use it for that. I do a lot of forum stuff while at work but can't soak up too much attention for a full guide just yet haha. I still feel I gotta prove my Flash before then anyhow.