i have a mix of crushed red peppers cayenne and paparika can i use that

Also, Aleppo pepper has a smoky note, so you could use smoked paprika or dried ground ancho pepper (alone or mixed with cayenne) to replace it.

Yes. I typically use either cayenne as a substitute for allepo pepper -- allepo is not as hot with a slightly tart flavor so I generally add half as much cayenne.