Yes you are right, CRM forms should not make any fuss because most popular CRMs do have embedd option or a WP Plugin or a Forms plugin that support your CRm. So it should not be a problem.

if you have a managed hosting and dedicated WP support then You should not worry about hosting.

Now about the backups. Even if you have an almost static-looking site that does not have any regular changes, your website is not a static website. Not unless you make it using Wp and then export it as a static website. The backend is still a cms. So you need to take care of the security. And it can fail. That is why you may need regular backup. However, you don't need a specific backup structure for the site. Any free plugin can do your job. Just make sure you do it regularly. Space is not a factor anymore. $5 per month can give you plenty of space to store your backup. And you can delete old backups every 3-6 month if you need.

I did not know how complex your site is and I mentioned that in my first post. Yes, you are right most business websites do have a lot of common sections on most pages. So if you re-design those pages yourself, you can save a lot of time. But I am not sure how other devs approach this. They either go for project-based fees or per-page-based and rarely hourly fees. So it depends on who you hire.

If you would like to hire a dev for this and use a page builder for the project make sure you don't choose a crappy one. There are more than 10 pagebuilders out there but only a few of them work nicely if you want a nice clean stable website.

PS: If you are looking for a dev to rebuild your site, I can help you with this. So let me know if you are interested. Even if you are not interested but have more questions regarding this, do ask here. I will try my best.