Thank you for the crash logs! I finally have an idea why it happens (2 or 3 minutes) after startup: One of the recent versions introduced automatic blockchain saving through the RPC every 2 minutes, and that can take more than 30 seconds (which is the WebRequest timeout I was using). I have set the timeout to Timeout.Infinite, as local requests may take any seconds. The reason why I didn't encounter this issue is that I am using an SSD, thus, my read/write times are faster than in the case of HDDs. (Probably, that's the reason behind TheNobodies' server being able to handle the situation without crashing.)
Also, I made the blockchain save only every 5 minutes instead of 2, but the wallet will still save every 2 minutes (as that's a lightweight operation compared to storing the blockchain).
Don't spend too much time on it. This feature will probably be fixed or removed soon.
https://github.com/monero-project/bitmonero/issues/50
It has already been resolved. The second picture is just a new feature for Timers, and it has been implemented too. By the way, the reason I don't yet use simplewallet is that rpcwallet is coming soon, and simplewallet's RPC functionality is not as extensive as the one in command line.
EDIT: I forgot to ask: How is your Qt project going?
What about the special wallet implementation? 
It works well. I used it for weeks in replacement of simplewallet and it fits my needs without bugs. I mainly focused or code architecture in order to keep it flexible and future-proof.
However, I keep it for devs only until more Monero Core features are implemented. (I will try to participate).
If you want, you can try the version I use in my Windows 8 (x64) tests here :
http://toh.neozaru.info/toh/public/bitmonero-qt-0.0.1.zip
About the RPC-free wallet, compiling with it is a tedious task because required code is not part of official Monero repository. Thus, bitmonero-qt can still be used with simplewallet/RPC.