I'm putting bulkhead hatches in my kayak, but as a 'day boat' my forward access needs are limited to inspection and maintenance. I've always needed two hands to close Kajaksport type hatches - I'd be a sight headfirst in the boat, legs flailing about. A knob or magnet closure might make more sense for a forward hatch - something you can easily work one-handed.

I wonder how well the block would work loading the boat - wouldn't the bags going forward and the tensioned line coming back get in each other's way? A common suggestion for no-deck-hatch packing is to tie a line to the first bag in, toss it up there, and stuff everything else in behind. A tug on the line will bring everything else with it to unpack.

For commonly used forward space, I'd skip the forward bulkhead/hatch. Floatbags to fill unpacked space would be easier overall. A few lash points installed where the bulkhead would go might be handy to help keep the gear forward in steep water.

Aft, I think a bulkhead hatch is a good idea, since the reach is right there. The shape of that bulkhead might speak against a commercial hatch though. That bulkhead is usually wide but shallow - you'd give up a lot of hatch area fitting a commercial hatch. A shopbuilt hatch could have a bulkhead that was only an inch or so proud of the hull - the rest of the area could be hatch. See Betsie Bay Kayaks for an example. http://www.bbkayak.com/Features.html