Personally I don't know much about editing players pictures. The following link will take you to the section of the forum where you are most likely to find the experts on that sort of thing so hopefully one of them should be able to help you with that.
Player Faces (Facepacks)
I've not previously edited players stats so my knowledge on that is fairly limited however I do know that you would have to adjust the players Current Ability (CA) I'm not sure how much you need to adjust in relation to the changes so you will have to find that out through trial and error or look to see if you can filter the players by the stats you want and base the changed CA off that.
to create a tournament and season I take it you mean to have a League and a Cup. If you don't want your teams to qualify for continental football then the league should be based in Liechtenstein as I don't think it gets any places in europe. It might get one for a created cup but as it doesn't have a league in real life then i don't think adding a league to it will generate the missing places. If you do want them to have european football then it's best to use a nation like Andorra or San Marino as a base as those teams aren't very strong anyway.
hopefully I've understood that last bit right, if so I can definately help with that, if not then you can correct me.