According to the wts ,the only grounds for scriptural divorce (free to remarry) that the wts recognizes is for porneia. If the child abuse that you mention falls within the wts definition for porneia then it meets wts requiremenst for scriptural divorce.
WTS or its agents CANNOT advise any individual to divorce for any reason whatsoever as far as I know. That is a personal decision and the wts will not meddle, however, the wts WILL tell you that you do not qualify to get a scriptural divorce and if you reject such counsel and remmary you may get df.
Regarding what to tell others about your mates sins or crimes, that is up to you, the wts may revoke your "privilidges" if they feel that you are bringing reproach on the cong or on the wts. Wise to keep private info to yourself.
The wts is also loyal and supportive to any active member, no matter how vile and dispicable that memeber has been. If such has been deemed repentant or weak, the wts ussually does not abandon such person seeking wts help.