If you're new to LBC, be prepared to take a beating first. First of all, you're competing with a lot of higher status guys that are already established. You'll have to sell at a lower exchange rate if you want anyone to bite, because there's no reason why anyone would buy from you if they can buy from someone already more trustworthy, if prices are the same.
Second, the site is littered with scammers. If you start to get higher volume, be prepared to deal with attempted scams on a daily basis. You might lose a bit as a learning lesson.
Now specifically for cash deposits, it's generally safe, but not foolproof. You're at risk of having your bank account banned if you get enough deposits (money laundering suspected), or even if the bank gets a tip off that it's a bitcoin transaction. Lastly, cash deposits are reversible. Not as easy as paypal, but easy enough (I recently just got a 4-digit cash amount reversed on me within the last 3 weeks).
Holy crap I have had many cash deposits from my bank from btc / bookies (gambling) I'm with wells fargo and this worries me. Had no clue they could actually close my account or reverse....