Add these commands to console/autoexec if you play without floating health
tf_hud_target_id_alpha 255
tf_hud_target_id_disable_floating_health 1
If you choose to use floating health, I still recommend typing tf_hud_target_id_alpha 255 in console. To center the names, open resource/ui/TargetID.res, find "TargetNameLabel" and change "textinsetx" "1" to "textinsetx" "10"
To disable pulsing health bars (low/buffed, navigate to custom/FLV (BLU)/scripts/ and rename HudAnimations_tf-NOPULSE.txt to HudAnimations_tf.txt, overwriting/delete the other.
For the bonus health cross, rename resource/ui/HudPlayerHealth - CROSS.res to HudPlayerHealth.res (overwriting or placing the previous file elsewhere).
To regain the team-colored triangle in the bottom right corner, go to resource/ui/HudPlayerHealth.res, search for "tri" and set "visible" from 0 to 1.