Price lower and lower... Coin is over?
No. Stop spreading FUD. The recent state of exchanges are causing some price suppression, as well as news on the BTC front from Korea and other sources. Recently on Stocks.Exchange the price jumped up to $32, so don't falsely accuse the coin of being over.
Good.
In fact if you look at the recent SPK price here, you can see the nice upward trend:
https://stocks.exchange/trade/SPK/BTCIs this exchange trust worthy?
I use it now and then. Its kinda slow with deposits and withdrawals, you have to wait like hour to for your deposit to arrive, but overall its fine.
Never had any problems with it. Yesterday i made an ETH withdrawal and it took like a day to arrive, but with ethereum network congestion that is understandable.