Sounds to me you will be like previous owner , won't spend on it, and get a texecom engineer in, hence the problem with bell and anything else , either way you need to pay someone to reset it do something for you
If you load defaults it won't brick it no , but you will lose all information and start from scratch , so aswell as whatever faults still exist , a load new ones will appear
Your probably thinking you can just buy a new panel and do it yourself , well good luck with programming it , it isn't the easiest of panels to work with if you don't know what your doing
Just being honest get a texe pro to help you , it will be worth it , or try loading defaults and hopefully within 6months it will be working how you want it to, paid extra for system , used unserviced