"Asking for trouble"? -- No, more like begging :-) Sunroofs are nice--I've always liked them and made the ones in my cars operational. But if yours is sealed up there's no telling just why. Possible reasons for such a "fix" -- 1. The drains are clogged - and/or 2. the seals are shot. 3. the cables are shot - and/or 4. the transmission (the crank) is shot -- or none of the above and just a former owner not inclined to deal with any sort of sunroof problem--big or small. The only way you'll know is to unseal it and get it all apart.
It's all fixable but if you have difficulty with fiddly bits it may not be a job you want to tackle. -- Dave