Hello. I have this Acer Palmatum for two months. Some weeks ago my family an I moved temporarily to the south of Portugal where a storm and lots of rain passed here and I accidentally overwatered the tree. (Here the temperatures are also around 30ºC, I don't know if this is a big impact on the tree since it doesn't get direct light; this was also the reason why I thought I should water a bit more). Now the leaves and the branches are a bit withered comparing a few weeks ago due to the overwater I think. The leaves are also more yellowish. So here are my questions :

1 - Some websites say to stop using fertilizer in bonsai after overwatering. I haven't feed the tree in about 3 weeks. Should I continue not to use fertilizer? Or since 3 weeks have passed I must use the fertilizer in order to replace nutrients in the soil?

2 - When I bought this bonsai at the store, the worker there said that this maple could only get direct light in the early hours of the morning. Should I leave 3 hours of direct sunlight? Or should I prevent the tree from getting direct light?

3 - And how can I get my tree back vibrant and with green leaves? What should I do?

(these photos are from a week ago so I no longer have those algae in the soil)

I hope you guys can help me I would really appreciated it. Thanks in advance!