Yes you should take hydrometer readings. No you won't hurt your beer opening the bucket to draw your samples.
Remember there's a cushion of co2 protecting your beer. Just be conscious of how/where you set down your lid while drawing your sample set it on clean paper towels, or just half on you bucket.
Or better yet have someone help you. Sanitize both sets of hands, your hydrometer and wine theif or turkey baster, have a friend open the bucket...drop your theif or turkeybaster in and draw a sample, then have friend slam lid down...
You Should be able to do it in less than 30 seconds.
Remember there's a cushion of co2 protecting your beer. Just be conscious of how/where you set down your lid while drawing your sample set it on clean paper towels, or just half on you bucket.
Or better yet have someone help you. Sanitize both sets of hands, your hydrometer and wine theif or turkey baster, have a friend open the bucket...drop your theif or turkeybaster in and draw a sample, then have friend slam lid down...
You Should be able to do it in less than 30 seconds.