Floor repair questions

[joe7670]

Yet again I have questions.

Anyone have any picks of what you have done to reinforce where the floors join after a floor cutout? Should I be running a stringer type under there attached to the other stringers or just a smaller piece would do?

Also the holes to the sides of the center holes in the deck do not have drains in my case. I'm thinking of converting 2 to hatches in which case I would definitely add a drain. Any reason to go adding a drain to each?

The foam in those side hatches is not even with the stringers. Would it be a good idea to get some more foam and pour it over the current foam to build it up to the stringer height they slice off the excess prior to floor installation?

The stringers have this hard glue type stufff on top which was what the floor was installed with. Ideas of the best way to remove this stuff? I', thinking of grinding down even with stringer and leaving the excess that's on the sides there. May provide a little extra surface area for the new floor to glue to.

Found a post where someone uses liquid nails to adhear the floor to the stringers. Couldn't find others. Is this the general consensus or should I be looking to use something else?