Definitive questions about API Policy are best sent to their team at api@twitter.com – sorry it’s taken a bit for me to respond here.
You start with a bit of a false premise, that the features Proxlet provides were the reasons for its suspension rather than the reason actually stated in the article ( http://mashable.com/2012/01/17/twitter-proxlet/ ).
I’ll turn the question around a bit though – when you read the developer TOS, Twitter’s TOS, its design guidelines and you measure that against the app you’re building, do you think it passes muster? At least the spirit of the guidelines?
As a general rule, Twitter prefers its objects to be identified and treated as unique entities. You don’t re-share or like a tweet, you retweet it. It’s best to follow all the “shoulds” in the display guidelines and TOS, but it is critical that you follow all “musts.”
Without looking deeply at your service, I don’t perceive any real issues with the features you provide – as long as you don’t surprise users or do users a disservice by editing their tweets, don’t provide an unsecured API or proxy, and make a good effort to display tweets as Twitter prefers (complete with all native actions a Tweet has: favoriting, retweeting, replying, and potentially following of the author).