The valves should not be bent, the X-Wedge is a "safe" engine, the valves do not hit the pistons even if the cam belt breaks. The full engine manual is available for free on the MTWC website "5 Speeder" page (link below), along with a lot of other good information.
To install the cam sprocket correctly you will really need to remove the intermediate cover and put a spanner on the cam flats at the back to torque the retaining nut up. You will also be able to replace the cam seal and inspect the needle bearing. The inter cover gasket is a large one that will probably get damaged at removal, you will need a new one. Gasket sets are available again now. All the instructions to do this job are in the manual.
https://www.mtwc.co.uk/wp-content/uploads/2018/01/SandS-X-Wedge-1.pdf
