At worst you can stop using this setup if its not good, so I dont see how it is any worse.
If it doesn't work, it would be a waste of resources that could have been spent on finishing the laundry list of "features" not implemented yet.
Instant Transactions - Requires peer review
- Decentralized Marketplace / Auction - In progress
Buy or sell goods/services in a distributed manner. All listings are broadcast to all nodes on the network in P2P fashion.
- Distributed Storage - In progress
- Multi-signatures - In progress
- Blockchain Shrinking - In progress
- Two-phase Payments - In progress
Software supported escrow transactions
- Voting System - In progress
- Reputation System - Will be implemented after Voting System
Account trust rating system. Check if sellers on the distributed exchange have a good history, if stock issuers pay dividends and if gateways honor their asset redemptions.
- Decentralized Mixing Service - Concept not ready - Cryptographers please contact core dev team members
- Distributed Computing - Concept not ready
- Smart Contracts - Concept not ready
The code that the node is running is also open source. It would be tested and so the only way I can think of that the node doesnt send the request to the service is if the server crashes.
I suspect some nodes could just collect transaction fees without forwarding the request to the "hub". Even worse, the node could send a fake transaction to the "hub". It takes bitcoin miners 10 minutes to confirm a transactions, so the Nxt network would not know the node sent a fake transaction for at least 10 minutes -- at least after one confirmation on bitcoin's blockchain.
I personally would trust that a peer reviewed open source solution that takes into account the Evil Bobs of the world will be more trustworthy that trusting some random employee at some random company. But, hey that's me. Maybe I am becoming a cryptoanarchist?
Absolutely not. Without some mathematical/cryptographic guarantee, I would take a trusted gateway over anonymous node. You need to provide mathematical proof to show such a system will work, and I doubt it will ever work without scam risk (or just technical failure)