I thought McCarthy was for freshmen only? USC Village has other housing for non-freshman I believe.
You’re correct @mhc006 . McCarthy Honors College is just for incoming freshman scholarship students. It basically will work the way that Birnkrant has in the past: Trustee and Presidential Scholars will be encouraged to apply and it will surely fill up because there are just enough spaces to cover the usual number of incoming Trustee/Mork/Stamps/Presidential students.
And yes, there will be other housing options in USC Village that will be made available undergraduates.
What would be a good second alternative to McCarthy? Birnkrant?
As for what will happen to Birnkrant -It will be demolished. 
It is unclear what will become of Birnkrant (BK) next fall. Location wise, however, BK is right next to the EVK dining hall and Leavy library (open 24h).
Nothing is getting demolished any time soon.
For freshmen, McCarthy Honors College is the only option available at USC Village. The other 4 buildings are for upperclassmen, mostly Sophomores.
Birnkrant is going back to general Freshman housing.
The good news is there are a lot more spaces available at McCarthy than there were at Birnkrant, nearly double.
For freshmen accepted this past weekend, the housing portal opens Tuesday morning (3/28). According to the brochures, there is a benefit to applying early due to first-come, first-serve processing. Is this a situation where first choices start to become unlikely if you wait until end of April, or does it happen within hours/days of the portal opening?
It’s only 12:26 and the portal already has too many logins at the same time for me to log on. does this mean i already missed out on getting my first choice??
I tried exactly at 9 it said too many logins so idk
Housing isn’t that hard to get in at USC. Most people get their first or second choice. @mgb1311 people want different things. If you apply today, certainly no worries at all. Getting what you want (first couple choices) is likely for quite awhile meaning first few weeks. They have room.
As @CADREAMIN suggests, you will be fine… especially if you plan on filing the application today… even if it has to be later in the day due to site traffic. Even more important than speed can often be locating a roommate and agreeing on your preferences in order exactly. That will make USC’s job easier, as they can satisfy two applicants with one room placement. And you can locate such over time and even change requests over time too. You are not locked in to what you put on your application portal today.
For future reference, log-on about an hour early… refresh every ten mins or so… have profile sections (3) all answered ahead of time (could have actually done it yesterday, as soon as they emailed you the password)… have special interest community application filed before (could have done it even up to weeks ago, if you wanted to)… and then at 9am Pacific, you can simply start the application - as you would already be logged in. Then, when you get to the special interest community page, skip the application (because you already did it or can do it later)… scroll down and confirm which one it is… pick the corresponding residential community and save / move-on. And of course have a credit card ready to go.
My daughter did all this and was done by 9:09 am.
Just food for thought for future years’ applicants 
Those wiser than me here ---- how do I review or edit my housing application? There doesn’t seem to be a way to “open” the pages again once they are marked “complete”? What am I doing wrong here? Thanks in advance for help.
log in and go to application at top and you should be able to move between the little circles that represent the various pages, I believe you have to hit save/continue to move off of a page.
Thank you @blueskies2day ! Yes – I missed save/continue!