How long is the coxsackie virus/hand, foot, mouth contagious 4? Is just when they r running a high temp or until the rash disappears?

Not known 4 sure. Coxsackie virus can be transmitted by nasal, salivary discharges, as well as by the blister-like rash that may appear, and by stool (poop). So even when the rash disappears, the virus can still be shed in the poop for weeks. Wash hands well!
First week. Coxsackie is infectious during the first week when you have a fever and blisters. Still infectious until blisters dried. Return to school/daycare rules vary. Some say once your fever is gone. Others say stay at home until blisters dry up. Good luck and hope you feel better soon.
Not a big worry. Hand-foot-and-mouth-disease is a viral rash caused by an intestinal virus (coxsackievirus). It is thought that infected individuals can shed viruses for up to 4-6 weeks. Keeping kids out of school is not generally recommended as the infection is generally self-limiting and is rarely serious.