Well, not knowing how to find collections in Ancestry can be fixed with some assistance and mentoring. :)
Searching Ancestry is a bit like going to the library and searching through the card catalog, you start by knowing a little about what you are searching for and then drill down from there. Rather than go into the how myself, here is an Ancestry blog that might help:
https://blogs.ancestry.com/ancestry/2016/07/06/how-to-find-the-collections-for-your-area/
Properly citing your sources is very important in any Wiki, including WikiTree. Could you trust the information on the link I provided above to domain names if the editors did not provide sources to the data in the entry?
It is even more important in genealogy. We have a burden of proof as genealogist. It's a bit more like science than a guessing game. If a profile on WikiTree is not properly sourced in a manner that any other genealogist can repeat, then the sources are meaningless.
In addition, like I said, providing a direct link to a record or even the image of the record is fraught with error. You can search the G2G forums and see all the posts by folks that now have broken links in their profiles because Ancestry changed the way the records in their collections are accessed. So sure, that doesn't cause an issue for you, because you have that person in your tree, and you can go to their profile in Ancestry, and click on the source there. But, no one else on WikiTree can do that.
As for whether multiple results come up in a search result, it's the same as searching in Google, you make your search parameters more specific.
In my example, if there were multiple "Stacy Glasscock" entries, I most certainly could add the date of marriage and the spouse name to make it easier for the next researcher.
For example:
''Virginia, Compiled Marriages, 1660-1800'', database and images, ''Ancestry'', 1997 (http://www.ancestry.com : accessed 23 April 2017), Marriage, 1799, Stacy Glasscock, Frederick County, Virginia, Spouse: John Payne Clark; citing Dodd, Jordan, ''Virginia Marriages to 1800'', digital transcriptions, Frederick County, Virginia.
Ultimately though, the leaders of WikiTree have provided us with a guide as to HOW to source our profiles. So that is what we should do to ensure that WikiTree provides a consistent experience for all users, provides the most accurate information as possible and our profiles meet the burden of proof for genealogy research.
All that said, if you really want to have a link to the record (knowing it may not work in the future) for your own purposes, you could do something like this example, where I am wrapping the source with the proper ref tags and creating a linkable title to the record:
<ref>''[http://search.ancestry.com/cgi-bin/sse.dll?indiv=1&dbid=3002&h=115109 Virginia, Compiled Marriages, 1660-1800]'', database and images, ''Ancestry'', 1997 (http://www.ancestry.com : accessed 23 April 2017), Stacy Glasscock, Frederick County, Virginia; citing Dodd, Jordan, ''Virginia Marriages to 1800'', digital transcriptions, Frederick County, Virginia.</ref>
This would create a link that works today on the title of the collection, but still provide the proper citation meeting EE and Wikitree standards. Then, if the link no longer works sometime in the future, the information is still there for you or any other researcher to find the record again.