Correct. Sun can't exactly protect you from modifications that infringe on the patents of others. But remember, the CDDL is designed to keep developers (including Sun) from suing each other over patents. It's in the link I posted.
No they're not, nowhere in your post did we find one person from Sun "promising" anything in that regard.
The promise is in the CDDL, plain language, further intent to stop patent wars shown in the links.
(1) for code that You delete from the Original Software
You don't get covered for code that you don't use. Sounds kind of redundant to me, but I'm sure there's a legal reason behind it.
(2) for infringements caused by: (i) the modification of the Original Software
As I said above, they can't cover you if you introduce infringements to the code.
(ii) the combination of the Original Software with other software or devices
They can't cover you if you combine CDDL code with other code that infringes on a patent.
All of those bits are designed to remove the possibility of patent wars with CDDL code, even patent wars started by Sun. Basically, if you introduce a patented concept into the CDDL (applies to Sun too), you either grant license to the patent or you lose your ability to work with the CDDL.
Once code goes CDDL, you permanently and irrevocably grant patent licenses to that code as long as the developer complies with the CDDL. Should Sun later restrict that to prevent forks, as that Sun exec said, you could simply fork at the earlier, more permissive license.
Face it, you lose. The plain language of the CDDL and loads of documented intent from Sun executives shows that forking while remaining free from patent threats over CDDL software is possible. All you have is a comment from one Linux guy soon after the license was released saying he doesn't think you could safely fork.
About the only other person you'll find to agree with you may be Pamela Jones of Groklaw, who is absolutely paranoid about non-GPL open source licenses (she is a Stallman ass-kisser).
FINALLY you admit forks can be sued for patent infringement, which is all I ever claimed. To provide patent protection for forks would be insane, obviously (to most).