It really does depend on what you you're looking to achieve. I love the words used by Apple way back when .. "Delightfully Capable, Surprisingly Affordable". I know I can bring great value to any business whether you use me a little or a lot.
Possibly my favourite question! And again it depends on what help you need and where in the process I am with my existing clients. From experience allow 4-6 weeks from first meeting to starting the onboarding process. Less if you're super quick at making decisions!
I generally have a minimum contract length of 3 months as I'm keen to work with businesses who want to make a serious commitment to their marketing. After that it's on month by month rolling basis until you're ready to rock'n'roll without me.