TheMaster

Just Use proxies for any kind of ratelimits steam ithink now applies dynamic ratelimits dont know for sure by yeah.
Use proxies 

yes after the trade the new asset id is visible so just set up a inventory poll and u should be good any steam trading bot does inventory poll but be careful not to set the poll too frequent u can get ratelimited very fast.
the old asset id is still in the event handler response so u have both the new id and the old one how i do it is i store a template of the doc in db then use a backfill script to fill in the new asset id.
Hope that helps
Regards

u can just add the proxies in the constructors of steam user and steamcommunity its that simple

If log on succeeds, you get a loggedOn event. Check the example scripts in the GitHub repo.

You'd want to call logOn for any error event, likely after a delay.

Catch the error event to prevent the crash, and call logOn again to kick off trying to connect.

It's not mentioned in the documentation, but you only get an eresult in the error event if a Steam connection can actually be established. If you don't have an eresult proeprty, you can assume there was a network issue.
Only you can properly decide the best course of action for your app, but if your network is down then yeah, probably all you can do is wait and retry until the network comes up.

steamcommunity.com's DNS records appear to have been wiped, preventing you from loading Steam Community (unless you have a cached DNS entry!).
This was temporary and is now fixed