I have a new theme I've designed (as a PSD) that needs to be developed as a Multisite theme, which will be used for 50 client sites (very basic, brochure-style sites...nothing complex). My biggest concern is to have the most stable and secure theme as possible. One that can be the best it can be to withstand the potential pitfalls of breaking during WP and plugin updates.
I won't shortcut quality when hiring a developer, so I'm making the assumption that code will be well written. I also plan on hiring someone who knows Multisite well, to do updates, in case something eventually breaks. Since I'm not a developer, I hope I expressed these question well enough so I don't embarrass myself too much.
A) Should I have a preference if the site is developed with a framework (Genesis, Bootstrap, etc...) or if it's written without a framework (just HTML5/CSS3/media-queries, etc...)? On one hand, I think a framework will present another layer or potential update issues, but on the other hand, I wonder if a well established framework (like Genesis) produces a more stable theme.
B) If a feature can be hard-coded vs using a plugin, is that a better option for long-term stability and security?
C) If you were to give me a few important tips that I should articulate to my developer, to create the most stable and secure theme for Multisite, what would you suggest?