How much should I prioritise the type of account (custodian vs cdp)?

Not so important.

to be on the cheaper side (with regulatory safety) custodian is better.

given the relatively evidenced fact that even professional (!) fund managers are bad longterm stock pickers, there is no investment related value for retail investors to attend AGM's.

Take note of the pros and cons of the accounts.

If your stocks are held in CDP custody, corporate action charges are usually lower, you get access to AGMs, and you'll be free to sell and buy though any broker.

If your stocks are held in broker custody, then you will probably have higher corporate action charges, perhaps even dividend handling fees, quarterly maintainence charges, no access to AGMs unless you request it, and you have to buy and sell through that broker. However, the trade off is usually lower commissions, which might make or break the deal for you.