Why up to 200BTC you ask? simple, builds trust much faster.
I don't want to sound mean, but why would anybody trust you more, after this? Each potential credit will be like a coin toss, either you pay it back or not.
The only thing that increases trust in a pseudonymous setting are positive credentials you're afraid to loose from abandoning your identity, and this money shuffling doesn't seem to qualify.
Sorry, English isn't my 1st language so lets see if I understand your post.
You are saying that higher BTC amounts do not mean I will be more trusted? I must say that it will. Seeing if I pay back a 200 BTC loan, it is more likely that in the future, if someone wants to buy something from me or loan me something 200 BTC or lower, that there is a much greater chance that I am trustworthy for that amount since I could have gotten it and ran away with it before if I wanted to and didn't.
The 2nd point you make is that I cannot lose my positive credentials? but I can! I believe that you can register at Heatware and give me a negative evaluation if this does not work out, provided you have proof (and I make sure the loaner has proof, like a PM with exact time I received it etc). Also, even if my OTC rating is low atm, if I lose my pseudonym, I lose the ability to show off my heatware for example. So far, my heatware has gained the trust of many, so losing that would be a big blow.
No loan is 100% safe, I'm just trying to not only prove my worth and that I am trustworthy now for these loans, but by completing my loans, I am showing everyone I actually am trustworthy. Noone can prove that they are not going to scam until the transaction is done, but by doing a lot of transactions, the higher the value the better, they still build trust. Higher value the loans are now, the higher the value people will trust me with.
Anyhow, AFAIK, I am risking all my positive credentials. With these, people actually trust me when I say I'm selling This CPU and RAM at 200$ and they send me the $$ through paypal gift (no fees) and are not surprised to see the items come in perfect condition in the mail a few days later. Also, I have invested a lot of time in my home forum, Techpowerup.com. This may sound silly, but my reputation alone there is worth more than 1000$ to me.