I'll explain:
1. They can basically start with any dojutsu around, but can only have 1 of them.
2. Upon choosing a dojutsu, the character is forced to follow all elemental and specialty requirements of the "origin", meaning for example: when starting with a sharingan they will need to start with Katon as specified by the Uchiha and depending on the choice of path their specialties will automatically have to include ninjutsu or genjutsu.
3. to rank up the chosen dojutsu they will need to follow the rules from the "origin" clan as well.
4. As specified by the Imperfect Self drawback, since they can't transplant anything onto themselves, they will never obtain two eyes of a single dojutsu and thus wouldn't be able to use for instance susano'o which needs 2 eyes or tsukuyomi. They also won't be able to get the blaze element as they are NOT actual uchiha anymore and thus also can't have amaterasu even when they would manage to obtain mangekyou.
5. lastly, their dojutsu is sort of treated like an implant would, with higher maintainance cost and activation cost.
Hope this helps a bit.
P.S. do note this IS supposed to be a restricted clan in the fashion of all dojutsu clans, meaning you can't just take one like this right off the bat and follows the same app requirements as the uchiha, etc.