In my honest opinion instructors shouldn't tell anyone to put so much restiance on their bike that they can hardly ride. So with that, just do what you feel comfortable doing.

There are different certifications, in order to actually instruct a true spinning class. The instructor shold have been certifed through Madd Dog Athletics. They will have a JGSI# if they did and you can ask the instructoe if they have that. Also you should be riding on the actual spinning bike. There ar so many other indoor cyclying type classes I couldn't even begin to name them all. A couple are CYcle Rebook, Kiser and Pace Line. As for HR training, YES your instructor should be giving you gidelines for your rides. Most instructors talk about the importance of having a HR monitor while you ride. You can check out more about that and anything else you want to know about Spinning at:

www.spinning.com.

Hope this helps.
Spinner777