Your answers looks good.
You can always refer your client to review online documentation on Oracle database 12c
The limit for table transactions is very high and whatever business they have, Oracle database can handle it.
Locking mechanism at database level is great, I don't think database restart is needed because most locking happens due to client and killing that session is sufficient,
I feel all answers need to be modified. The questions 1 & 2 are related. When they say specs its about the version, database configuration & capacity and how many transactions can it handle etc.
The question 3 is more about ERP and not about the Database as such. in EBS we can have Multiple Organization configured and any locks related to other organizations can/cannot impact other organizations based on design or exact scenario. However I can give appropriate answer if you provide some background and answers to below questions.
- Firstly, can you tell me if they are implementing EBS?
- Are you hosting their EBS?
- Firstly, can you tell me if they are implementing EBS? << Yes, they are planning to use it
- Are you hosting their EBS? << It will be in Oracle Cloud.