hi JyEn,
I just learn about this website and chance upon your posting.
Hope I am not too late in posting my reply to the issue you face with baby dino.
Potty Issue:
You mention in your posting that baby dino has been caged since born until he is 1year old. There is a possibility baby dino has learn not to eliminate in an enclosed area . The one year he has been caged has got baby dino to learn "when he poo in an enclosed area where he sleeps and play he has to step on his own poo and pee". You may want to either enlarge the area of the playpen so that after peeing and pooing in one part of the pen he can still sit/sleep/play in the other part or leave his crate inside his play pen where the crate will be his sleeping area and the pen will be his "attach toilet". (see sample on attach photo).
Stomach touch:
Not all dogs like "belly rubs" as some dogs see it as "forcing it into submission".
For dino to accept touches on the stomach start by rewarding the dog for body touches ie touch dog at various body parts and after each touch followed by rewards (such as doggie treats).
In this way dino will associate touches on it's body parts "= something good".
You mention dino doesn't like it , you may want to eleborate what you mean by "doesn't like it" ie how dino response when you touch his stomach (eg he move away, he growls, etc ? ).
Hope that helps for now. yawn... bed time
Cheng See