I agree Robbin that there's no evidence that Sir Thomas is aggressive to Lady B or that she's afraid of him... but that could be becuase she's so torpid htat she never does or thinks anythng at all so she never does anything that might incur his disapproval... so she never thinks that she might have anything to fear...

Yes he IS IMO generally soemone who has high expectations of his family and their behaviour... though it seems to me as Ive said that iwth Tom he expects good behaviour but does not do much to try and enforce or encourage it...
but WRT Lady B. Sir T, while he clealry finds her boring, does seem to be genuinely polite and respectful and forebearing of her stupidity and her laziness...