I have d-link products, camera's, etc can I put Sense between my modem and my d-link router?
If so, would there be any conflict?
If not, does SENSE allow for d-link products to run through it?
Yes you can but if i have understood right you need to put the dlink router in bridge mode in order to extend sense network.
Also should put the modem in bridge mode to avoid double nat.
There are few posts about these same kind of setups which can help also.