First of all, I would like to congratulate you and thank you for designing this extremely entertaining and addictive game. Then I would like to make two suggestions.
My first will be to have the ability to build ourselves our grips and our guards. The grips could be made from wood that we can cut ourselves. The rare wood could be used for grips of higher quality. The different kinds of ore would produce different qualities of guards.
My second idea would be to change the concept of sleep. It could be a selection of hours that we wish to sleep, Less sleep time would mean less time before being exhausted. Or to be able to sleep when we want and not only when we are exhausted. It seems to me that time management would really be simplified.