1) whether amendments in SEBI Act and Co.s Act since past 2 attempts can be left by me for Nov. '12 exams??.......because half-of them (I think) is not relevant for our exams..

Your thinking may be such as because you are already reading from the last 2 attempts. And as you had already experienced the paper pattern .......then you already know what should you neglect or not ....  But still last 6 months amendments ....  I don't think should be ignored. Amendments hoti kitni page ki h yr ...  Just read RTP for them ... It would be more than enough.  Suppose even if the question doesn't came in exams ...then even you would have an overview of the same.
 

2) I am finding it difficult to study as this is my third attempt and I'm fed up of being in C.A. and studying..

And about the third attempt .... first of all stop annoying from your failure.Your words are showing that you don't believe in your work. And if you faced failure again ....,then there are even 70% chances atleast that you would leave CA

1. Are you really ready to give exam right now in Nov ? e.g like you would be able to complete your syllabus and revision in time  + what your inner instinct says ........

if the ans is no ..... then I would say don't even give exam no matter how much pressure you feel from peers  and family.

2. Mistakes  Area  :-  I don't know about your marks obtained from last 2 attempts. but still these would be enough to give you a proper glance of what  is the main area in which you were weak ....

count it and recheck it ...whether you have worked upon that or not ....

3.  Difficult to study  :-  The main hinderance is the faulty planning. Suppose you know you have to complete  a lesson today .. you can easily do it. But if you didn't know what to do ... then you'll surely fall .....

set pure targets like

• chapter 1 in law + 10 questions of SFM and 1 chapter of ISCA  or whatever according to your limits and days left
• maintain your diary whether you really did the work or not ....
• Revise whenever you think you have done too much ...   give 1 hour for it   for a subject
• for example you have done 5 lessons in law ... but now you fear that you haven't done it or  should revise it .... or I can't recall it what I have read in last lessons ..... then you  can have a quick revision instantly in an hour ....
• Such quick revisions will really help you in boosting your confidence level because it's the main killer of your concentration . Just give 1 hour for quick revision not more than that.... because revision's main purpose is to remove the fear  and clear doubts.

once you are mentally calm ..... There would be no further attempts of CA  final... you will surely be CA.