I personally was thinking to purchae LSZH but to my dismay I am troubled by this bglman.dll issues which looks like to persevere

. I never liked this way of sale/purchase
We tried to explain it very clearly in the manual and in the FAQ in this site: the Addon Manager is needed for the scenery to work, because the scenery use it for many features, it's some kind of FSUIPC that does for sceneries what FSUIPC does for airplanes or other products.
This doesn't have anything to do with sales system. That's only *one* of its features. Unfortunately, since it's the only one that the user get in contact with, many have the wrong impression that the only need of the Addon Manager is to implement the Trial version and sales.
This mechanic of purchase is still troublesome and may I suggest to consider other ways of selling this scenery.
If we switched to another sales system, the Addon Manager would still be there. But, if we had sold the scenery via (for example) Simmarket, by now you already had spent your money, and still being struck with an issue.
Nothing will happen if the demo process is unimplemented.
Exactly: now you understand why this sales system it's better for users. It's our best interest to fix problems fast.
Oh, and kindly have a look at servers response time, 10 minutes to get logged in is way too much.
You mean the forum ? No problem from here, it's very fast. I'd wait other user report about slow server speed, before investigating further.