Paypal and checkout stage look?

Hi all,

Over the past few months we've been using various Paypal methods for our checkout on-site, and I am basically looking for some feedback of experience with how I should go about setting out our checkout stages/process.

So, we are on a shared hosting provider, so hosting payments on-site is not viable at present (PCI Compliance..).
We are with Paypal because we are in the highest band of payments receiving so our fees are very low - due to us using such through eBay & Amazon..

We have been testing Paypal Standard, Express, and looking towards Pro Hosted (we are signed up to use Pro).

Our checkout is the Quick Checkout mod by Dreamvention, which I think is very easy to use, and looks much better than the default checkout. However, I am not in great understanding as to what to include in the checkout process on-site, because customers inevitably get re-directed to complete the payment stage regardless of which Paypal setup we use, should we therefore not ask for any payment/shipping address information on-site to speed up customers' checkout process?

It would seem that customers have to input the data twice if we ask for such, and I therefore fail to see any logical benefit to asking for it on-site? Am I correct in thinking this way? I am a little unsure with Pro Hosted as I haven't bought the mod for it yet and implemented it, but does this offer significant benefits over Standard/Express?

I believe Express doesn't allow for "guest" checkout with credit/debit cards but asks the user to sign up to Paypal if they haven't already got it, Standard I see has no modification like Express with the logo etc... And with Paypal Pro Hosted, does that bridge the differences between offering Standard/Express and also allow for 3D secure implementation?

Sorry if i've got mixed up in all this, as you may be able to tell i'm not too great with having choices to make!

THank you all for your time,

Regards,

Luke