I am available for all questions etiquette related

ooh, you're good, Etiquette Expert!  here's a question, perhaps more out of curiosity than etiquette.  in reference to ex2 - since the store's cards are a no-no, how do people find out where the bride & groom have registered?

Word of mouth.  Traditionally, if you want to know where the bride and groom are registered, you call up the parents of the bride to ask.  You can also ask bridesmaids.  As long as the parents/bridesmaids aren't advertising for the couple it's good.  I think the point of all of this is so you don't receive an invitation in the mail that is like "we'd really like the honor of your company at this important event in our lives, and here are a list of places you can buy us presents to thank us for bothering to invite you" 

The official position of the couple should be "oh please don't feel like you have to get us anything!  We just want everyone to come and have a good time"  and then you let the parents and wedding party do the gift solicitation for you.

ohhh I see this one on Etiquette Hell alot.  I also remember it from my sisters wedding since she had the problem having a VERY small wedding in Mississippi, but also knowing a ton of people between her and Spencer. 

There are NO "givesies-backsies" in weddings.  period.  It's an uneven basis for comparison.  The weddings you were invited to in the past were held at a different time if your lives where you may have had a different circle of friends.  It was held at a different location and had access to a completely different budget.  You can't feel bad because someone had more money five years ago and was able to invite everyone under the sun. 

Bottom line, you have to pick the size of the wedding YOU want under the budget that you can afford.  If that means that some people can't be invited that's what it means.  If anyone asks about being invited or says something rude of that nature you can say "We haven't finalized the guest list yet.  Unfortunately we're working with a small budget and won't be able to invite everyone we want to"  This should politely send the message.

On the other hand, anyone who may be expecting to be invited and then isn't may be hurt and you have to prepare for that.  I know it sounds petty but weddings are huge events in people's lives and not being included may mean the end of some friendships.  My sister didn't invite this one girl from high school and they never spoke again.  You have to be ready for that. 

But don't feel like just because you were BFF with someone five years ago you should have to invite them anywhere now.

-Etiquette Expert