Welcome to our Forum and thanks for your confidence in our advice.  I'll be happy to answer.  HIV is sexually transmitted through unprotected, penetrative sexual contact and is not transferred through transfer of genital secretions from person to person without penetration.  In fact, even conservative agencies such as the CDC state that there is no risk for HIV from mutual masturbation in which partners get each others genital secretions on one another.  Similarly, there is no substantive evidence that other STIs are transmitted by hand to genital contact.  There is no reason for concern and no reason for testing related to the activities you have described.  In answer to your specific questions:

No, no risk.

2. Can I resume unprotected sexual activity with my long term partner?

Yes, no reason for concern

3. I have young children is it safe to change diapers give baths ect.

Your children are quite safe,.  You can bathe them without concern. 

4.  Should I see a doctor in my area and get tested?

There is no medical indication for STI or HIV testing related to the event you have described.

I hope these comments are helpful. EWH