Turning your current work into a full-blown coherent sleeve is possible - the real quest will be to find the right artist. IMHO the current work has too many objects in a small space - so you're going to have to open to some re-work or even cover work if you want a quality outcome.
Where are you located?
Right. Good application will provide lasting results.
Many feel that over long periods of time that the style (even when done well) has a higher potential for becoming less discernible just because there is no outline to "hold it together".
The 1st day I limped for a few minutes every time I was sedentary or had my leg elevated for awhile. Just a blood rush related thing.
Saniderm is a wonderful thing, especially to basically eliminate the chaffing and/or contamination possibilities.
I drove 2.5 hours after getting my lower leg done. Fatigue was more an issue than pain.
Now the next day you might have some swelling - and those 1st 10 minutes after getting out of bed are going to be fun!!
I've never heard it that way - but I'm assuming that instead of using watered down black to make variations of grey that he's using specifically formulated grey ink(s).(?).
That picture looks quite nice for the style.