Mohit Tyagi Sorry about the delay in responding.

1. I maintain an excel sheet for all feature requests, pending things etc. (except bugs). So I guess you can call this as some sort of a backlog. I would still do the whole urgency, impact, effort for even those items. If you don’t know the solution, if it is urgent enough and impactful enough, probably spend a day or a few days in thinking about the solution and the complexity so that you can estimate the approximate effort for the final solution and then plug that into the formula.
2. The value of parameters (impact, effort) are mostly based on gut feel and intuition. There’s no science to it. Would be great if you can accurately estimate both the impact and the effort but that’s not practical especially when you have a long list of items.