So that says you can't have anything extra, does it say you must get the same?
After a little looking, it looks like that is the case, but there could be a bit of a grey area depending on company policy. Here's a better paraphrase I guess.
"To the extent that an employer offers other non-seniority benefits (e.g., holiday pay or life insurance coverage
- I assume travel bennies fall in this category) to employees on furlough or a leave of absence, the employer is required to provide those same benefits to an employee during a period of service in the uniformed services. If the employer's treatment of persons on leaves of absence varies according to the kind of leave (e.g., jury duty, educational, etc.), the comparison should be made with the employer's most generous form of leave. Of course, you must compare periods of comparable length. An employee may waive his or her rights to these other non-seniority benefits by knowingly stating, in writing, his or her intent not to return to work. However, such statement does not waive any other rights provided by USERRA. (Section 4316)"
Is your company required to provide pension payments, health care, etc while on mil leave?
For health, yes - not sure about pension since I have none!

But after a certain period of time, they can charge an extra 1-2% or so premium, but must provide it if requested.