If you have the money, Colchiro is right. Just get a new tablet.
Otherwise, since your NC is already rooted, I would recommend Paranoid Android 2.99 (JellyBean 4.1.2) as it is pretty decent (not perfect, but decent). Way better than CM 7.
Samsung Tab 3 (7 in) • Deletrious ROM V1.6 /TOSHIBA Thrive • Pio's Team Baked BlackBean ROM 4.1.2/Samsung Galaxy Note2 • Temasek v37 kitkat (4.4.2)/HTC EVO 4G • Decks Reloaded ROM/EVO Shift• JellyBelly ROM/Samsung Galaxy Note I (i717)•CM11 (4.4.2 kitkat) /Samsung Galaxy S3 •DanKang 4.3.1 ROM