I am planning to move all my bitcoins from local market to MTGox because of liquidity. Is this a wise idea? I know everyone on this thread would be negative about this - but are they scammers - or just some problems?
I really wouldn't recomend MtGox to anyone.
If you want liquidity for larger volumes, Bitstamp and BTC-E are much better options.
For small volumes (a few BTC) in Kraken is the best. My last SEPA withdrawal on Kraken was on my account on the SAME DAY

Right now volume on Kraken is a bit low as it is only a new exchange, but its good choice for the future. Importantly its a exchange with all registrations in order and you can choose what verification suits you best (4 levels). Also LTC volume in Euro is building up too slowly.
BTC China i am not so sure, as far as i know you cant get money out of china.