Load balancing host named site collection

Question

I am jumping into the realm of host named site collection. While the learning experience has been good, still there are some questions unanswered. Please bare patience since my questions are long.
- I have a non host header site on port 80 that has https certificate added to IIS for supporting app store in https mode.
- I tried to created the host name site collection using https in this default port 80 non host header web application and was greeted with error. Then i extended the web app to different  zone with port 443 . Then created the host header site collection
with https with web application name for extended 443 one. Creation went in fine.
- I tired to use IPs on now extended IIS site and bind certificates on that one. The site does not load. I do the same again in the default zone iss site, bind ips on that one and site loads. Now question is even though host header site collection was created
using extended web application url , why binding had to be done on default zone IIS site?
- Second test, i changed the authentication mode for extended, no effect on host named site collection but as soon as i changed it in default zone it reflected in host named site collection. I am confused why it needs extended zone url to create the https
site but every change done in default zone is getting reflected on this host named site collection.
Now for load balancing , it works fine with IP? But how to load balance these host named site collection using url. I talked with f5 team and they said i need to send some reply query string from each site. Where do i do that? Or is it even needed? 
Accoring to this link : https://devcentral.f5.com/articles/name-based-virtual-hosting-with-ltm
. If the site hosts an application, though, the monitor should request a dynamic page on each webserver which forces a transaction with the application to verify its health and returns a specific phrase upon success.
For application monitoring, the recommended best practice is to create such a script specific to your application, configure the monitor Send string to call that script, and set the Receive string to match that phrase. 
Has any one done this before? I tired to search for resource regarding this for iis or sharepoint but was not able to get anything.
Thank you for your patience for reading such a long question. 
Adit

Answer 1

first part of question:
Default Web Appliction in port 80: Creating https host named site collection fails.
Extend default web application on port 443 : Https hostnamed site collection created when web application name is passed for extended web application on port 443. This means this site collection is associated with this extended web application correct? But
all the changes made in IIS only reflect if it is made to port 80 web application. Also changing authentication scheme from Central Admin, only changes on default zone reflects on site collection not the one in extended web application? Why  if the site
was only created on extended web application paremeter, changes on default are reflecting on it but not from extended.
Second part of question:
Each Hostnamed site collection when load balanced thorough f5 using IP for 3 WFE uses 3 IPs for each. This way we will run out of IPs pretty soon. I want to know if there is way to load balance these sites using Hostname or anyother paramenter through f5
and if any body has done it? 
https://devcentral.f5.com/articles/name-based-virtual-hosting-with-ltm link talks about sending reply string
from application but i do not know where to set it up or how to do it? No resources in the net. Just asking if any one else has done it. 
Adit