App for limited or restricted audience

Question 1

You can achieve this by simply following below steps. It may help you.

App store Provision Profile - You need to create provision profile for App store distribution and make build(.ipa) with this code signing identity.
When xcode ask you for distribution type select Ad-hoc distribution and save .ipa file in your computer system.
So now this .ipa is same as you download from app store And no limited to 100 device.
Please follow this steps to create .ipa file.
```
Launch Xcode 5 (Product -> Archive to build the archive)
Goto Window -> Organizer 
Select the latest archive and click the Distribute button
Select Save for enterprise or ad-hoc deployment
Select your App Store provisioning profile and then Export
Choose a location to save the .ipa file
```

Create Manifest file - it is an simple .plist file. I am also giving example below.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
   <key>items</key>
   <array>
     <dict>
         <key>assets</key>
         <array>
             <dict>
                 <key>kind</key>
                 <string>software-package</string>
                 <key>url</key>
                 <string>http://www.xyz.com/foldername/AdHocDemo.ipa</string>
             </dict>
         </array>
         <key>metadata</key>
         <dict>
             <key>bundle-identifier</key>
             <string>com.xyx.AdHocDemo</string>
             <key>bundle-version</key>
             <string>1.0</string>
             <key>kind</key>
             <string>software</string>
             <key>title</key>
             <string>AdHoc Demo</string>
         </dict>
      </dict>
     </array>
 </dict>
 </plist>

The keys in the above file that need to be modified for your app are:

items.assets.[1].url
items.assets.metadata.bundle-identifier
items.assets.metadata.bundle-version
items.assets.metadata.title.

Create HTML file - Create simple html file with below hyperlink. You need to provide URL of your menifest file in below url tag.

<a href="itms-services://?action=download-manifest& url=http://www.xyz.com/foldername/AdHocDemo.plist"> click this link to install </a>
Authantication -This steps are for your distribution of app but everyone can install build who has the link of HTML file. So you need to create authentication for access above HTML page so only authorize member can download application.
By doing this way you dont need to go with apple app store. People/Member can download app from your own website. It is calling Ad-hoc/Enterprise distribution.

Question 2

You can simply add authorization. And give logins/passwords to the club members. It will require an autherization server, of course, but it's the only idea that I have at the moment. And you'll have to provide a test account for the Apple review team when you will submit your app.

Question 3

You can distribute the Add-hoc version of your app which will be installed only on the authorised devices

Question 4

You can have an enterprise release of the app i.e add the udid of all the people's devices you want to give access through and distribute the app through private network. The number has a limit, 100. You might need more then one account if number is large.

EDIT

Enterprise Distribution (Enterprise Program, $299 / Must have D-U-N-S number)
The iOS Developer Enterprise Program is intended for companies who create proprietary, in-house iOS apps for internal deployment within the company only. A valid Dun & Bradstreet (D-U-N-S) number is required for program enrollment.

Ad Hoc Distribution (Available in Standard Program, $99)
The Standard and Enterprise Programs allow you to share your application with up to 100 other iPhone or iPod touch users with Ad Hoc distribution. Share your application through email or by posting it to a web site or server.

if you are registered with enterprise development program with apple you can do it link