The phrase "at least" when talking about making your monthly payment very clearly means you are allowed to pay more than the maintenance payment of interest. As anyone who have ever had any sort of credit-card or other loan should know, anything beyond the interest payment goes against the principle of the loan unless you're assuming, rather disingenuously, that the extra is just a gift to the person that counts for nothing.
Modern day, yes, but who knows what banking or underworld
standards are in the 2070s? Can you even pay off the
principle from In Debt? Nothing says that you can. It says you have to pay the interest owed at least. Extra could just as easily go toward next months interest, leaving the character always in debt until certain terms allow him to pay off the principle (such as him having paid karma on the quality...oh my). Now, you can disagree with what I've said, but let's just take a gander before we go down that road.
The things you mentioned are less House Rule and more in the realm of "The GM screwing with a player that deserves it for abusing a loophole until he coughs up the Karma."
Qualities are, by definition, an innate part of the character. Keeping a quality relevant to the character is not GM Screwery, it's merely following what the rules state. A character that owes 0¥ is not
In Debt. Debt, and being in it, is in know way an innate part of the character any longer.
Now, let's look further into what the books say:
SR4A, pg. 271
Negative Qualities
If the gamemaster approves, a character can work off a negative quality by undertaking severe changes as appropriate to the quality. For example, a character with an Addiction quality must work hard to kick the habit, resisting the temptation to relapse for a significant period (chosen by the gamemaster). If the gamemaster feels that a character has made the necessary changes to shrug off a negative quality, he can allow that character to pay twice the quality’s BP cost to remove it.
First sentence, making severe changes appropriate to the quality (such as paying off the principle of a debt) is subject to gamemaster approval before it can even be undertaken. If the gamemaster does not approve of the "working off" being taken, he doesn't have to approve it.
Runner's Companion, pg. 102
NEGATIVE QUALITIES
As with Positive qualities, Negative qualities can be chosen at the start of play. With the gamemaster’s approval, Negative qualities
may be bought o with Karma per the rules on p. 271, SR4A. If the character does not possess the requisite Karma, she may
have to wait. Also note that this expenditure does not encompass the Costs of any associated augmentations, medical treatments, schooling, etc. that the gamemaster may require. Additionally, the gamemaster may decide that certain qualities can only be removed after roleplaying through their resolution (such as removal of a dependent or curing a mental illness).
The underlined portion shows that the qualities in RC (such as In Debt) still require karma to buy off
and follow the rules from pg. 271 of SR4A (the first quote). The italicized portion makes it clear that other costs (such as paying off the principle) are in addition to the karma cost required. In other words, paying off the principle
is part of buying off the negative quality, it's an additional cost. If the player chooses to not pay of the principle as part of buying off the quality, then the gamemaster is free to, and should, make sure the quality has not been bought off. After all, that's what the character is wanting.
None of my proposals were instances of the GM screwing the player, they are instances that show the method you proposed is flawed at it's core. If the player chooses to pay off the principle to get rid of the quality (which requires karma
and nuyen expenditure), the GM has to approve, and the player has to wait until he has the requisite karma (blatantly stated in the rules). If the character is choosing to pay off the principle and not get rid of the quality, he isn't taking all the steps to get rid of the quality.
This is no different than an addict going through rehab, not buying off the quality, and relapsing as soon as he hits the street. Too bad, so sad, here's your next fix. It's no different than the brain surgery not working for TLE-x when karma is not paid. It's no different than the Uncouth guys etiquette training, not taking when karma isn't paid. The fix only works, if it's the full fix, which requires karma plain and simple.
I'm simply saying that ACCORDING TO THE RULES FOR REMOVING NEGATIVE QUALITIES, the GM can GIVE YOU THE OPPORTUNITY to buy off the quality. The rule does not say they can FORCE YOU to spend the Karma do so.
It's not a case of the GM
forcing the player to buy off a quality. That's implying that the GM forced the player to pay off the principle. It's a matter of the GM
forcing the player to
either A.)buy off the quality or B.)not buy off the quality instead of trying to use a flawed loop hole to get stuck in the middle. The bottom line here is that the changes to buy off the quality (paying off the principle) are only available with GM approval. The player can only do it when the GM agrees, and, by the rules, if he has the karma required to buy off the hindrance. The GM sure does have the right to say, you can only pay off the principle if you buy off the quality, and force the player to do both at the same time. It's completely within the rules, as is not getting rid of the quality if only one portion is done.
