Altona DG Wohnung - 1Jahr Untermiete + Übernahme

I am renting my nice and cute flat from 01.01.2025 in super nice and quite area in Altona.
It is a last floor, 5th floor, very quiet and friendly neighbours.
The flat has 2 rooms, one bedroom and a big living room, that you can use as dining + working + chilling area.
The flat does not have any Keller, but it has as little storage space (as 0.5 room).
The kitchen room is equipped with a nice new kitchen, it has oven installed and has space for the dishwasher if you need it.
The bathroom has a shower and space for the washing machine.
The warm rent with everything included is 870 EUR (including Internet).

The flat is partly furnished, and I would like to have a little payment for it. I would like to leave my sofa, dining table and 4 chairs, refrigerator, new closet, bed, mattress, commode and night table next to the bed. I would like to have 900 EUR for all of this furniture.

The flat is ideal for one person, without any pets, unfortunately. For a couple, this is slightly too small.

Currently it is only possible to rent a flat as a subrent for 1 year, with a possibility to fully take it. If you want to have a flat earlier, we can also do it, but then the fee of 840 EUR should be payed to the real estate company (since my minimal renting period is 2 years, and it will be over in Feb 2026).

Please write a bit about you, what are you doing, if you would be okay to pay for the furniture and take over the flat overall in one year.