CAN I SUBMIT AN IOS APP THAT DOESN'T SUPPORT THE 4S? IN IOS

This must have changed since you asked this question. In iOS9, you can cut off devices not supporting 64 bit architecture. See this article:

http://9to5mac.com/2015/06/10/ios-9-older-devices-lose-support-apps/

Thats great (from a developer and legacy support standpoint), especially since 4s usage is really dwindling. Problem is, it cuts off a lot of the iPads (over 80%), since they only switched to 64 bit when the iPad Air was introduced. So beware of what you cut off in tablet world with this approach.

I'm not sure if you can target specific devices though, which would be the most ideal.

Now, with the pending release of iOS 10, iPhone 4s support will be dropped. This means that if you make iOS 10 a requirement you won't need to support iPhone 4s. However, you'll have to wait for iOS 10 to be released (Fall 2016).

remove armv7 will remove support of 4s

2017 July

Since you're talking about aspect ratio, you still need to support the iPhone 4S resolution (640x960) because iPad running iPhone apps use the same resolution. We got two iPhone apps rejected because they were not compatible for iPad. It is mentioned in their documentation as well,

2.4 Hardware Compatibility

2.4.1 To ensure people get the most out of your app, iPhone apps should run on iPad whenever possible. We encourage you to consider building universal apps so customers can use them on all of their devices. Learn more about Universal apps.

The approval is inconsistent because one app that we submitted got approved without the support for 640x960 resolution but the next update was rejected when they found the issue. It is best that your apps support to run on iPad.