Thats to prevent spam. Often forum moderaters on any site adopt similar rules or move posts to the correct category.
Nushares is the underlying backbone asset to Nu. Because of the recent BTC spikes/crashes and volume has gone up for Nu. Nushares are built to assist Nu community with the $1 peg per nubit, increasing NBT assets via grants, and NBT interest rates (and perhaps burning shares, dont quote me on that because its been a while since I read all the documentation). NBT is designed to be pegged to $1 (which will fall against BTC just like USD does), so if you are looking to isolate yourself from a NBT/BTC crash, either you would hold BTC or hold nushares (ongoing buyback at 32k a day). Heres where you can see what exchanges Nushares, Nubits, and BTC: Exchanges and Liquidity — Buybacks: $32,833/day
Ive never been aware of changelly supporting NBT. The exchanges Nubits supports are above.
As for how slow it is, Ive found that internet connection speed (providers are better at 12-5 am local time too) and how long the client is left open is important to sync speed. The more recent blocks are slower to download, just like bitcoin as more people use it and the blocks have more data in them. I suggest you open the client up at night when you are sleeping or doing thing away from keyboard. If you leave it open for 24 hours a day, thats less than 4 days. If you dont want to wait 4 days, then sol? I pretty sure that speeding up sync time is on the developers long term roadmap but it wont be available immediately.