Redirect 301

[Shanaki]

Hello,

Case study: 
I changed all the links from an online store as follows:

Before: www.domain.com/store1/category/product (link to a product, in magento e-commerce)
After: www.domain.com/category/product (link to a product).

Basically I removed the stores, and made 1 default / base store, and put a 301 redirect (from .htacces).

My question is:
1. How bad i broke the seo, cause i was no.1 on 30 keywords with these structure of links, and these kinds of link had page rank 2-3.
2. Does redirect 301 from old link, transfer the Page rank?
3. I should modify all link from link building  to the new link? I mean urgent?
4. Does google will reindex the keywords with the new links?

Thank you in advance. 
With respect,
Shanaki

[DennisSeymour]

Hi!

1. As long as the redirect is properly set, then it's fine. It's out of your hands on what Google will ultimately decide on. From my experience, it just indexes the new url, on the same spot. I drop normally a few spots but bounce back

2. It does transfer pagerank. Some say it doesn't transfer fully which is backed up by studies but for me, I just keep it simple. It does pass PR, how much, is irrelevant because it's usually good enough. Tradeoffs

3. For those that you can change, yes. But since there's a 301, the urgency should be put to your internal structure first. Fix the whole site, make sure there are no holes

4. I'm not sure what you mean, but Google will index the new url if your 301 is there. If you mean rankings, they yeah, it will pretty much appear on the same spot. You might drop a bit though