On the tithing issue, Jesus taught:
Matthew 23:23
23 Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone.
Here Jesus calls the scribes and Pharisees hypocrites for omitting the weightier matters of the law. He does mention that they pay tithes but they have omitted judgement, mercy and faith. However, in the end, he tells them that the weightier matters of the law they ought to have done, and then he states, "and not to leave the other undone". So Jesus did believe that tithing was a less weightier matter of the law than judgement, mercy, and faith but did recognize that it was still a matter of the law and should still be practiced.