Luis,
Send it back. I had one that did the same thing, and it pretty much had all the issues of yours. Bought another one to see if it was any better. It wasnt. I complained on the forum about it. Big mistake. Bottom Line in my opinion? they have major QC issues, but they will work with you to try and fix the problem.
I managed to fix all the issues by disassembling it and reassembling I must have opened/closed it at least 100 times by now. I am pretty sure it's good to go.
The blade is not longer hitting the liners, and the liner lock has worked 100% of the times.
