moving from shopperpress to responsive shop theme

I really love the responsive shop theme and have already purchased it for the give away price.
But if I move to the shop theme, i will have 2 problems.
1) with the shop theme, i will need to set “add shipping charges”to YES as the default is unfortunately “NO” that means i need to manually change 600 items and publish again.
2) All my url links will change as the new structure is adding product in the URL link, and even if i manually change all 600 listings with a plugin to remove the /product/ I did not find a way to do the same for my tags and categories.

Some of my tags have very high google ranking , this means i will lose all of that and need weeks before the new ones are discovered.

Is there a way about these 2 problems i will be facing.
Please help
Nadia