Problem is that not only can you do those requests at that time, but you have to be avalible in order for people to want to request from you. So what if you just were open all the time and avalible for requests? Then you could do your request when you have time. That's what I would suggest, because people don't often request from shop workers anyway. If you were closed every so often, nobody would request from you.
5 is a perfect ammount. 5 or more examples will let you be a worker in my shop. Also remember that you can feel free to tell me when you are unavalible for requests and I will say you are closed. I'll PM you if someone has a request for you to do. I'll explain further details once you are a worker.
Today for sure. If you don't have to do anything tonight. I'm going on vacation on Wednsday, so it'll be really hard to trade. Monday and Tuesday are the Weekends, which pretty much everyone, including you, has to do something, so I can trade right now if you want.