Inherit field value from parent record (between modules with one to many relationship)

Hello dear community members,

I’m looking for a way to inherit fields (and their value of course) between related modules (one to many relation).
For example, I would like to show in every Contact the Industry and the Type of the parent Account.

One more example. I have the following one to many relationships (the first two are custom):
One Account --> Many Projects
One Project --> Many Cases
One Account --> Many Cases

When a Project is already related with an Account and I relate a Case with this Project the Case should be automatically related with the Account of the Project.

Can anybody please give me any hint on how to do this? Where should I look?

Thanks in advance for any help.

Accounts and Contacts is many-to-many BTW
if you want just to show info from parent - use logic hook after_retrieve

regarding second case - u could also solve it for sure by logic hook