Need advice on pricing a large SMM client (TV, radio and news channels)

I’m a freelance SMM and I’ve been approached by another marketer who was contacted by our local television and news station for SMM and content creation services. They’re looking to revamp their presence (their current socials look a bit dated) and this would involve managing multiple brands under their brand umbrella. The marketer who reached out will handle strategy and liaise directly with the client and I’d handle the day-to-day execution.

It would include:

• Managing 5 social media accounts (4 radio stations + 1 TV station) on FB & IG.
• Providing guidance to their in-house team for the news account (we’d create templates and help them with writing captions/headlines, but they’ll do most of the posting)
• Creation of Canva templates for each brand
• Approximately 35 posts per week across the 5 managed accounts
• Monthly content planning call with the client
• Making a monthly content calendar based on that call and their strategy and goals
• Graphics, captions, and scheduling for all accounts
• Responding to messages and comments, with direction from the team
• Monthly report
• Some on-site content creation (like behind-the-scenes)
• Payment for a second person to work with me on these tasks

Here’s where I need some advice...This sounds like a BIG client, and I’ve worked with large ones before who ended up being overly demanding and expected posts at all hours and on weekends. Where I live, SMM is still not taken seriously and there's often a lot of scope creep with clients and I want to protect myself from that. I mentioned it to the marketer and he said that it shouldn't be a problem, but you may get the odd late night message.

I typically work 9am to 5pm Mon-Fri, and I'd ideally like to keep it that way. I also told him that I have other clients that I plan to keep working with and I wouldn't be available all the time.

Therefore I was thinking of charging extra for any out-of-hours work, as well as a setup fee for creating the initial design templates. I was also thinking of having a set amount of content creation hours in the package, and anything extra would be an additional fee.

Is this the right way to go for a client like this? I've never had to price a package of this scale before.

How would you charge for something like this? Would you do an all-inclusive monthly retainer (including payment for the second person), or charge a flat monthly rate plus add-ons for out-of-hours work and content creation?

Any feedback from people who’ve managed multi-account clients like this would be greatly appreciated.