your changes are nice, both from a thematic and functional standpoint, although the nos. seem to be a bit too high, maybe make towers only get the HP/dmg, depending on lane which took first tower. for example
if bot lane got 1st tower, top and mid shd get more dmg(prevents tower dives)
if top lane got 1st tower, bot and mid shd get more HP(adc can't chunk tower down easily)
if mid lane got 1st tower, bot and top can get both buffs(most played-around lane in game)
if turrets still end up being weak, then:-
Buff turrets resistances(more Armor and MR in early game, but scale down slowly and slightly as the game progresses)
Turrets should only be dealt damage if the damage dealer is within the turrets’ attack range. (stops things like kindred and baron empowered cannon minions killing turrets from multiple screens away)
Baron empowered minions should only be granted bonus resistances, nothing else.
my first change would heavily increase early laning phase time, but wouldn't affect champions who rely on splitpush tactics to be relevant.
my second change is self explanatory.
my third change is to make the baron empowered champ the main dmg dealer, not the minions, the minions are just there to give more time for the champ to take down the turret.