VUGen Protocol Analyzer - How to analyse the protocol for recording in Loadrunner

Analyzing protocol for VUGEN recording :

Most often, it is found that tester attempts to record a web application but face some of the obvious challenges. What is the good deal then? Let me explain some of the situation in this context -

Query 1 : Hi, I am new to Loadrunner and want to record a web application but I am not able to record it. The Loadrunner launches the web page but does not record the actions.

Query 2: Hi I have recorded the application using multiple protocols - HTTP and AJAX. But while enhancing the VU Gen script, i am getting some different code snippet against AJAX call used in my web application. Please suggest me how can I overcome the situation.

Here above two queries have been churned out to put across the situation of a beginner and somewhat expert tester. The above two queries need to find out a prominent way of recording a script without any glitch.

Here some blind folded people explain the concept of VUGen Analyzer - "This is the best way to find the protocols." Now there are many cases when you use the VU Gen analyzer and still face the challenges as asked above in Query 2.

Some thumb rules for protocol analysis in VUGEN -

1) Protocol analysis is not a science but an art of understanding the architecture of System Under Test (SUT)
2) Protocol is not about which technology your application is using - For example if your developer has used .NET to develop a web application (aspx pages) does never mean that you will pick .NET protocol for recording a VUGEN script.
3) Most of the web applications work perfectly with HTTP protocol. The only thing you can do is tweak and play your script with some enhancements.
4) AJAX calls can be recorded without even selecting AJAX protocol in VUGen. That's true ! What you need to do is record the application on HTTP protocol and an AJAX transaction will be recorded in custom code. Now that custom code can be used to customize your request.
5) Use .NET protocol when you application type is desktop/windows and is built on C# /VB.NET
6) Use SAP protocol for SAP applications
7) For citrix application use ICA protocol and give proper configuration command while recording the application.