Yes, bet365 is a trustworthy online gambling site. They are licensed and regulated by the UK Gambling Commission and have been in business since 2001.
The true odds indicate the probability of winning a craps bet. For instance, if the online casino reflects the true odds at 2:1, this infers that, on average, you can expect to lose the game twice for each win you make. In other words, true odds indicate your chance of winning craps.