I feel like virtually none of them mean anything for a Trump vs Biden. Like if Rs win the VA House and Senate all it says, is moderate Republicans are still able to capture Virgnia in off years. It doesn't mean Trump can brute force himself a win in a state that voted against him twice by a good margin.
Well keep in mind state legislative candidates are far less known by the public than major statewide candidates are and with no statewide election in VA this year , the legislative elections are close to as generic R vs Generic D as you can get . Given that republicans need to win statewide by 5 to take the VA senate , a win for the GOP would mean that democrats are losing ground in the suburbs and in the perception game .