If I take a distribution of contributory or conversion assets from my Roth IRA, can I repay this amount back at a later date or am I limited to $2,000/yr. in contributions, no matter what?

Example: Suppose I roll over $10,000 into a Roth in 1998 and contribute $2,000 each year for 5 years. I then withdraw $20,000 to buy a second home. Am I limited to still putting just $2,000/yr. into my Roth IRA in the following years or can I exceed that in order to repay the amount I withdrew?

You have 60 days to roll over a distribution back into a Roth IRA. After that, the money cannot go back. You can always put $2K of new money into a Roth, as long as your income does not exceed the limits.