Hi Leo:
Since I perform these types of analyses for $25, you'll be giving me a raise, lol. Since I'm not too worried about the money, here's the easiest solution you can implement in order to track your visitors completely, from start to finish.
The best, easiest solution is to duplicate your site from that landing page forward with unique URL's and structure. As you can see, it would be simple to do and provide all the tracking you need, short and long term.
Regarding performance of your Adwords campaign, I will be glad to look at the stats you have. I can check such things as overall CTR rates for each keyword phrase used and, perhaps, make a few suggestions for improving your campaigns.
Please try to remember to use keywords in the new navigation tree instead of any series of numbers, letters or other characters which would have no meaning to the search engines.
I hope this solves your main issue of tracking your visitors. If you need any more help, I am available through various means. Skype, most messengers, and email as well as phone.
Thank you for your time,
Don Hatton