Easier process to edit data?

I just tried to find out which "version" of "Mark Miller" is part of "Dead Cert (2010)" (https://www.imdb.com/title/tt1499220/fullcredits/?ref_=tt_cl_sm) - and didn't find him. So I took out the BluRay at just to add him - and watching the end credits I had to find out that he is not the only one missing. Additionally a load of the cast is listed as "uncredited" altough they are and so on.

Well, not sure if there is any other way to edit the profile of the movie a little bit easier: For me this is so exhausting checking at every added actor "I don't know if he/she is part of IMDB - let the team decide". And if you take a look at the screenshots below, practically 90 % of the data are wrong. The allready mentioned missings, the wrong "uncredited" plus a huge load of roles listed totaly different in the credits.

I presume that there is no alternative way to edit the site? And to be honest: This is too much to do for me. My plan was to control my collection. But now on all 5 or 6 movies I have to add missing cast, do corrections, send screenshots etc. So if someone is more experienced than me in editing, would you be so kind and correct/enhance the cast as credited? The missing headline on the first site is "The Paradise Crew". Many thanks in advance! For me there are too many actors with several persons having/using the same name....