1) OTP = One Time Programmable. Putting "OTP" in the search field could easily turn that up.

2) You can use external program memory regardless of internal ROM contents - pull EA pin to ground to use external program memory.

With questions like these, you need to spend some time reading the "8051 Bible": Click on "Links" on the left, search for "The "bible" ch 1 family architecture" and read the first three chapters. That will give you what you need to know about 8051 architecture.

- Lee