[ssjGoku69]

RBC calls it HomeLine.
TD calls it FlexLine.
CIBC calls it Home Power Plan.
BMO calls it Readiline.

It doesn't matter what it's called since the underlying structure of the credit is the same. I'll be calling it a Home Equity Line of Credit (HELOC) as the generic term.
As everyone else has said it before, getting the HELOC at Prime Rate (2.70%) is pretty good. Most financial institutions would be offering it at Prime + 0.50% (3.20%).

RBC Interest Rate vs ???:
Since you wanted to know how the RBC offer compares with other financial institutions, at where I work, there are pre-selected clients who can get a limited promotion of Prime minus 0.50% (2.20%) for a few months + legal and appraisal fees waived, but then it'll go back to Prime rate. But for everyone else, it would be Prime + 0.50%.
Prime rate is pretty good, but double check to see if RBC is offering that rate as a promotional rate for a limited time or if that is the permanent ongoing rate.
Also, try and get your RBC Advisor to waive appraisal and legal fees if you can. They would cost $250 appraisal and ~$350 legal with my experience.

Flexibility
You would be able to payout the full amount of the HELOC without any penalty. The only thing is that if you wish to cancel the HELOC, then there is a small discharge fee of $75 in British Columbia.
If the HELOC interest rate of 2.70% is lower than a Mortgage interest rate overseas, then I think you would be better off using the HELOC for that property purchase if the payment amounts are the same.
e.g. a $1500 monthly payment would be better off with the lower interest rate since a larger portion of that $1500 payment goes towards the principle.
The hard part is ensuring you're paying enough off of the principle each month. If you do choose to use the RBC HELOC and make interest only payments, or very small payments towards the principle, then it could get more expensive than the foreign mortgage at the higher interest rate.