Living Closely Together
A smaller living space means that you and your partner will have to get used to living much more closely together. Think about how you will manage that.
Living afloat full time is very different from a 2 week holiday on a boat although that is an excellent start point.
There is very little privacy aboard a cruising yacht and little niggles can become massive eruptions very quickly. Keep calm and talk it through!
Happily, there is more space than you think if you organize carefully.
As well as the communal area, there MUST be a separate comfy spot for everybody where they can sit and read, play games, watch TV, use a computer or listen to music without disturbing the other. On nice days the fore-deck, cockpit and aft deck will get a lot of use but when it's raining you need to allow space below for everyone to chill out.