Corporations and Indian-US body shops are way ahead of H1B. So, what about L-1s? I believe many L-1s are actually employees of sub contractors of the American corporations. I'll defer to the experts.
The department told the GAO that it is in the process of changing the systems used to track the foreign workers.
Guess who is changing the systems (I bet)? :>)
On a real serious matter I ran across another government report about national security issues of exporting technology. While there are some rules for exporting technology there appears to few rules for using H1B workers where they acquire knowledge that effectively transfer forbidden technology when the workers return to their home countries.
I believe you to be correct on both counts. Homeland Security should be labelled asleep at the switch if they fail to adequately address both of your points. Here's a fact - among L1s doing IT work in the USA are hardened anti American pro ChiCOM types, not only from the PRC, but from amongst the Chinese ethnic groups living in other Asian countries. We ought to be worried.