Yes, I will try my best to have available all the manuals for free.
No, there is no limit for how many PDF files you can download. But please don't use any downloader/spider/grabber programs to download all the PDF files from this website. Everything is good in moderate quantities.
Yes, you can. But downloading in multiple chunks/sections is not available.
While I have scanned each file personally with multiple antivirus programs, you could scan them again after you have downloaded them for the peace of your mind.
You can use the contact page link above in the menu and send me an email. Any feedback or help is appreciated.