I'd say rough handling is when the GP squeeks in pain. It's good that you're trying to be gentle with them-they have fragile little bodies. But that doesn't mean you need to be afraid of them or of hurting them.
When you have them out for lap time, choose a spot that is comfortable for you-a couch, your bed, or favorite chair. I usually go on my bed propped up with some pillows. I'll have the piggie on my chest and settle them down. Sometimes this means a blanket as they like to hide and be comfortable themselves. I also think that having the piggie on the chest is good as they're above your heartbeat-personally I think it's calming. Like those "soothing sounds" alarm clocks. And, if you'd like, bring some veggies for the piggie-they'll start to associate lap time with something good.
Hope this helped and good luck!