"They have pasty white skin, flexible body and extendable tongue. They also have the ability to swallow and spit out large objects, just like how a snake swallows a prey whole."
This portion of the description I'm assuming was to do with the Soft Body Modification technique, so you should edit it out unless you intend to make these clan jutsu of their own.
Typically for a forced negative characteristic to count as a true drawback, it comes with the stipulation that you not take a positive characteristic to balance it out. I'd ask that at least one of those forced negatives adheres to that.
All three of your jutsu need to have their cooldown times at least doubled.
Hardening Mud Snake- I'd like to see this limited to one post without incurring some kind of drawback yourself. We are beginning to crack down on any form of paralysis. That being said however, I'm less opposed to this because of it being physical bindings, but I still need more details about what it takes to break it. i.e. What rank of strength would a character need to break free on their own through brute force? Suiton jutsu can not be the only method to break free from this. Any offensive jutsu of B-Rank or higher should be able to break the mud.
Rebellion- When I asked you to specify damage, I meant give numerical values, not direct me to the jutsu guidelines xD. Typically jutsu should not be doing max every type of damage at their rank. If you want to maximize impact force, you'll have to minimize cutting/piercing damage done, if any. Also, keep in mind that each individual snake will not be doing B-Rank damage. That is the damage the jutsu does when they hit together.
Retreat- Limiting how many people you can protect with this isn't really necessary. As long as you can get them within the protective range of the jutsu, you can shield them.