I did some early payments. If I authorize a payment ahead of time, it's still the same amount as if I authorize the payment on the due date.
Of course, people using the term "refinance" as you described don't need to be scammers in general. Most people don't have BTCjam loans as their sole income but not everyone can immediately convert their non-BTCjam income to BTC to pay back loans when needed.
They can also just be incompetent borrowers who don't intend to scam but in the end still don't pay back, in which case the arbitration process would be started by BTCjam and net-Arb and you get an arbitration award. Arbitration awards will be accepted by most courts and you can get a court ruling in an accellerated process per mail, which will of course depend on the legal environment / judicial system of borrower's and lender's country.
I heard that some people have negative credit card balance and transfer the balance from the old credit card to a newly registered credit card repeatedly without bringing the balance nearer to zero, but still they are not prosecuted for credit card fraud or ponzi.
There's also the possibility that the borrower has invested too much into other loans that are not yet funded, so that the payments of his own loans are not all covered by his balance and he has no BTC off-site. I just recently noticed that I can't cancel investments into loans that are not yet funded, but I have to wait until funding failed or until funding succeeded and payment is made back. You can sum this up as incompetency too.
Some borrowers also have multiple loans at different terms and different interest rates to offer something for different types of investors, which might be seen as suspicious by some people.
In any case, you are right to pay attention to signs like you described, I wouldn't invest in such loans either or if I invest then after doing some research. If I don't invest, if no harm is done or if I have nothing more but a suspicion, I wouldn't feel appointed to give any trust ratings as I don't aspire to play the forum's enforcer for the protection of investors, but that's just me.
I must add that my own loans were
not tied to BTCUSD exchange rate. In a scenario like drewster's loans that are tied to Bitstamps BTCUSD exchange rate, the payments would vary I suppose.
See here
https://btcjam.com/faq/loan_typesMtGox linked loans
This loan type has its amount linked to the bitcoin exchange rate for a given MtGox asset. The payment size in bitcoin will fluctuate over time following the exchange rate that asset.
If I understand this correctly, if you would borrow 2000$ in BTC linked to MtGoxUSD or BitstampUSD, you would still need to pay back 2000$ in BTC. If the BTCUSD exchange rate drops, the amount of BTC needed to pay back the loan would rise. If on the other hand USDBTC drops, the amount of BTC needed to pay back the loan would drop too. Please correct me if I'm wrong.
I would be interested in the email that you got in answer to your email to drewster's employer
https://bitcointalksearch.org/topic/m.4552011