Your fh looks good but you are missing some fundamentals in the swing. If you watch your video you can see there is an inconsistency of where your take back position actually begins. I understand that the fh shots were all relatively different but you are missing some core components.
You are trying way too hard with your current fh. What I mean is that it appears you are putting a large amount of force into the shot in order to make it penetrate through the court. Instead you should focus on improving the fh progression alone. If you follow the core movements your form alone will be enough to produce your current pace. Once you have perfected that and add power and spin into the shot there is no telling what you could do with it.
There are two fundamental problems with your fh, the first is your take back and the second is your follow through. Your have virtually no follow through and here is what I mean by that. In your fh shots you are exerting additional energy to STOP the racquet rather than allowing it to continue its follow through. This is actually quite normal and it a mental challenge to teach yourself to continue the swing.
Go back to the basics and find a way to create a structured forehand. Every fh you hit should contain the core fundamentals -
Your bh needs more work than the fh. I would suggest you focus on improving one specific aspect of your game at a time. The main problems with your bh are timing, positioning and stance, footwork, take back, swing path and follow through. Do not misunderstand me your bh is good but is missing a lot of fundamentals
luvforty nailed your slice. You simply chopped at the ball. All slicing should begin over your shoulder and you should be looking to use a continental grip.
I would say you are a level 2 player. You are attempting to overpower the ball rather than using consistent execution. If you focus on the basics and work on form and footwork the timing comes with it.
Feel free to ask follow up questions here or by pm.
Good luck mate