Ok here is my advice from a crappy bowler like me who has been coached by Billy Hall and Wendy Mac, you have some of my main flaws so i will work with you to fix them.
Timing is late from not setting the ball into the swing plane, as Billy taught me you need to learn to walk by the ball. You do not need to push the ball away per say but learn to get the ball started by the 2 nd step. I repeat do not push the ball out or up but just let it start to go into the swing during the 2 nd step.
Lead with the ring finger feel like you are reaching for the floor while keeping pressure on your fingertips, if you practice this method it will relax your thumb more if there is a grip problem it will known right there to be fixed.
Leading with the ring will help keep you from the dreaded chicken wing motion, i have another trick to help keep your left shoulder always ahead of your right shoulder.
With your left hand on your 3 rd step push your arm staright ahead of you and twist your thumb clockwise to keep the left shoulder ahead. This will create strong rev rate and project the ball down the lane to a breakpoint.
Feel like you are landing the ball on the lane, keep your hand under the ball and keep your hand open on the follow through as jeff carter or pdw. Whever your hand goes it goes but get the arm to at least even with your head for the follow through.
Long and low as you can go, for me with a messed up left knee this is why i am not very good. I throw the ball pretty well but cannot stay on my slide long enough to really drive through the ball the way i know i could when i was younger.
pm me for any more advice if you try anything and if it works for you like it did for me, I probably coach better than i bowl that is my knickname in 2 leagues. I have worked with Billy Hall, Wendy mac Pherson, Sam Baca and Paul Renteria for many many hours, i can watch a bowler and help fix them easier than myself even though i have learned to make my injured method work for me.
--------------------
JDT A MORON AND CERTAINLY NOT A GENTLEMAN
BIGGEST LOSER IN LAS VEGAS PERIOD!!