Preliminary floor plan and layout

I'm starting to plan out the interior of my tiny house, prior to applying for a building permit. The exterior dimensions I'm currently looking at are 12' x 32'. My wall studs need to be 6" due to insulation requirements. This leaves me with an inside area of approximately 11' x 31' or 341 sf. The combined living room and dining area in my existing house are about this size, so I can walk through these 2 rooms and accurately visualize the spaces.
(I am also considering building 14' x 32' to get a little extra width; that is the largest I would go so I could still build it by myself. Nothing is finalized at this point.)
I've sketched out a preliminary floor plan below and would like some input from fellow tiny house enthusiasts regarding my thoughts below.

I had originally planned on building on concrete piers. I am now considering subcontracting out a full basement for the house since I understand the price is very reasonable in my area. This would double my inside space and give me lots of storage for out of season items in the basement. It also opens the possibility of having a root cellar for vegetable storage. If I go ahead with this, I will need a trap door in my floor for inside access to the basement. I will need to know where to put the opening prior to framing the floor platform. I am thinking of putting the opening at the side of the house, between the kitchen and the front door. I am thinking of a 4' x 2' opening.

Windows and where to put them? The front door and deck will face north and what little view I have. In good weather, I expect the front door to be open most of the time, letting in light. I was thinking of putting 2 windows on the south wall for access to sunlight. The south wall faces the forest. The kitchen area will need 1 or 2 windows and the bedroom will need one. The bathroom will probably have a small horizontal casement window near the ceiling. Any thoughts on window placement?

I will have a bed on the main floor. This may end up being a retirement house, so at some point people will no longer be able to climb a ladder and will need to be able to sleep on the main floor. I have placed the full sized bed at one end of the house in the corner. I had originally thought of having an interior wall between the bedroom and main living area, but I think the house will feel more spacious with an open floor plan. I can hang heavy shades from tracks on the ceiling, to provide privacy when someone is sleeping.

We need closets, but where do we put them? In the interest of keeping things open, I have drawn the closet in the corner opposite the bed. This would give me space for a good size closet and still be out of the way.

I will have 2 lofts, one over the bedroom area and the other over the kitchen / bathroom area. Both could be used for sleeping if needed. The one over the kitchen may also contain a water tank, if I decide to go with a gravity water system for wash water. The open ceiling over the central living area will be about 13 feet high.

I'm not sure that a Dickinson boat heater would be able to heat a 340 sf area. I may need a small wood stove. If so, I need to position the stove so there is sufficient space from the walls.

As I have mentioned in previous posts, this house is intended to be off grid, using a 12V DC system powered by solar panels and a rain water catchment system. My lot is close to a large fresh water lake, so I can always bring in lake water for washing purposes if there is a shortage in rainfall. When I wire the house for 12V DC, I may also add 120 V AC wiring with blank outlet boxes at the same time. I wouldn't have to connect anything, but if someone wanted to connect to the grid in the future, it would be easy to do. I was thinking of putting in an empty fuse box inside the bedroom closet and routing the 120 V wiring to the box. I plan to have a battery box outside the house on the south wall. This would contain my batteries, charge controller and fuses for the 12 V DC system.

All comments on my layout are welcome.