So I'm designing everything in mobile Safari and I know that phonegap is essentially a stripped webview but...

Question: Will my application will run better in phonegap? (revised below)

a)I imagine my navigation and core app will load faster as the scripts and images are on the hard drive. Is this True?

b)I assume since they've been working on it for 2 years now that they may have made some optimizations to make it quicker than just an average safari window. Is this true?

(Assuming both html5/js/css code bases are pretty much the same and app is running on iOS.)

Update: Sorry, I meant to compare apples to slightly different apples.

Question 1 revised: Will my app see any performance benefits running with in a phonegap environment vs standard mobile safari? (compare mobile - to mobile)

1b) In what ways, other than loading time has phonegap optimized performance over standard mobile safari?

Follow ups: 1) Are there any pitfalls, other than large libraries, that may cause phonegap to suffer a serious performance hit vs stand mobile safari?

2) Can I mix native and webview rendering? (i.e the top half of my app is rendered in with html/css/js and the bottom half native)