Hi Charles,
While there are much more experienced "harvesters" lurking here on Greg's Board (Greg being one of them!), to answer the first part of your question, no, the casinos don't want you to take their roulettes. This is because in Roulette the player dictates the value of the chips.

Let's say that Greg walks up to a Roulette table on Wednesday and "colors up" for $40 with each chip worth $1.00. He then proceeds to deftly relieve the table of a stack of 20 chips, and makes a clean get-away in that fancy limo of his! Thursday he returns to the same table, colors up again with the same color as the day before, only this time he buys in for $200 and the chips are worth $10. Now, just as deftly, he returns the chips he procured on Wed. to the new stack and BAM! turns $20 worth of chips into $200 just like that! The casino just don't like that!

I'll let someone else expound on the joys of owning a complete set of these little gems.

Regards,
Jim in San Diego