Do you like my Titan 29" Hatch/water proof improvement?

[Bigbore]

I got it used and it comes with leaks from Wire Drive and the screws through the transom and with nothing to seal out the water under the hatch.
Here is what I made to make my Titan water proof:
As adviced in one previous thread I made, I have sealed the drive shaft with silicone tube and o-rings and it have been working perfect:


So I have sealed the screws with hot glue:



Then I have made a transparent sub hatch with lexan 1mm thick that I can seal with waterproof tape. It provides a perfect seal against the water. Here I was testing it with a pool of water over the sub hatch:

[Bigbore]

So I have thought to fix the hatch with screws and fill it with self expanding foam that helps floating the boat in case it flips over:






Are these good ideas?