JackLee

Yep, you are just swinging with your arms and hands. Your lower body will not respond to that. You are also moving your upper body toward your target in your downswing. These two faults prevent you from swinging through correctly. Your left elbow bends and your hands flip the club through impact. You need to learn to lead and power the swing with your body. You might want to do a search on Google for "body powered professional golf swing". The master key instruction that I mentioned earlier will come up along with several others.

You both might be helped by the golf swing master key instruction. It makes your lower body movements lead your down and through swing perfectly.

On second thought, with my limited practice time, I think I will just keep swinging inside-out with both long and short clubs.

Sounds reasonable. I guess we should start practicing.

Like Erik said, you cannot swing the clubhead straight down the target line. That can be done only with a putting stroke. With any other swing, the clubhead travels on a path that is circular or close to circular. Maybe your pro is trying to get you to swing slightly inside-out. With a slightly inside-out path, the center of the clubhead will be a bit outside of the target line for a short distance after impact before coming back to the inside. So, with this path, your clubhead would be traveling in the general direction of the target longer. A slightly inside-out path can be done while using a stance that is parallel to your target line, but that is not the easy way. It is much easier to do it from a closed stance. How much closed is something you should experiment with.

A closed stance makes it easier to swing a little inside-out. You might want to experiment with that.

Just musing about the misuse of another word or phrase in golf, IMO. It seems that a toe line, hip line, or shoulder line that is parallel to the target line has become known as "square". Square to what? Back to the op's question: My shoulders could be close to parallel to the target line at impact. However, I use a very closed stance, which makes a big difference. How could you have parallel shoulders at impact while using a parallel stance? Maybe you could do it with a big axis tilt, or a big flip .

"Your arms need to get ahead of your body movements." Only well after impact. Momentum!

In a good swing, it is obvious that the lower body leads the downswing, but can you make your lower body movements perfect every time by using a lower body key? Sounds like a lot of practice. I prefer to make my lower body movements subconscious so they have to be perfect. If you have any interest in that, the instruction I use is "The Golf Swing And Its Master Key Explained" by Noel Thomas.

I don't look at the ball. I look at the turf just behind it. That turf will still be there after impact and I am still looking at it after impact.

Here is what I posted about this in a previous thread: Flipping is caused by an arm swing that gets ahead of your body movements. Learn to lead and power the swing with your body. You may want to do a search on Google for "body powered professional golf swing".

I never think about my hips. I do think about making a good shoulder turn by pushing with my lead shoulder. My hips turn as they are pulled by my shoulders. I have stopped at the top and checked my hips. They are turned about 1/2 as much as my shoulders.

You could be decelerating. I have read that this is a common cause of shanking.

You cannot go by the flex that is stamped on a shaft anymore, especially between different manufacturers, and sometimes the same manufacturer.

Good answer. Just what I was thinking.

My lead elbow bends some at the top, but it is straight again before and through impact. I use a little muscle tension to do that, but it is mostly done by the centrifugal force with a little help from gravity in a well timed release.

Okay, here's one guess. If your hands are more forward at impact than they were at address, that may result in your clubface being open at impact.

To make the lie angle fit, keep your knees bent a little more at address and throughout your swing.

Shots going left could be pulls, or it could be that the lie angle of the club is too upright for you.

Hitting dead straight consistently is very hard to do. I think most pros hit a slight draw or slight fade for their normal shot.

To make it easier to swing inside-out with the longer clubs, try using a closed stance. Trailing toe about 1" further from your target line than your lead toe with your mid irons, up to about 2" with your driver. Clubface should still be square to your target line at address before you take your grip.

The rubber tees should make no difference if they are the correct height for you.

The easy and cheep way to a good swing is somewhere in this thread. Did you miss it, or did you dismiss it?

IMO, anxiety is usually the cause of shanking. Fear of shanking just makes it worse. It goes something like this: Muscles tighten, backswing becomes too quick and incomplete. Arms get ahead of your body movements, forcing the club outside of your plane. You have to do something mentally to get rid of the muscle tension and concentrate on making a full, free flowing swing with perfect timing.

With a proper grip, your left thumb should support the club at the top and should stop it at about 90 degrees to your forearm. So what grip are you using that allows the club to keep going?