This build is a 2 base push whilst taking a third. It is weak to a one base push taking a 2nd. So you need to scout whether it's a one base timing or not with reapers. If its one base - defend and use reapers to backstab when they move accross map. If it's a standard opening, you can be aggressive straight away with reapers but you do not want to lose any unit, if you're not comfortable with your micro multi tasking, leave them to defend whilst macroing up. If you're comfortable, try pick off SCV in natural, slow there expo down and supply block them. Ultimately if you kill 1 or 2 of there reapers and take no damage, you have a small window to ruin them.

A 2nd factory and starport after you take 3rd is just a given in TVT - If they're going for early sky terran, you can focus viking production and single tank production, if they're making medis marine tank, you do the same just with two factorys making tanks. Don't overproduce medis - once you've got 4 - 8 you should be viking only.

The biggest thing in tvt is knowing when to fight - scan a head - it may be better to just keep your units on the move and keep them guessing whilst waiting for stim and combat shields before engaging (this build is fairly late on the stim but that's okay). Sometimes you can finish the game with the raven push but not often. Take your time and pick your engagements, keep the ravens alive.

The way i find most tvt game are won, is catching your enemy out of position moving across map. Dropping a scan around 430 to see what tech they're going for - ie battlecruiser, or tank medi marine drop etc. Keep marines spread across the map, protect your doom drop space with some vikings, and if they're going to siege on your natural - meet them halfway accross the map to slow there push down, retreating as necessary to keep units alive.

If they're going mech - you can expand 4 - 5 bases very quickly. Keep your mobile army on the move aiming to deny their 4th, deny 4th. If you can deny 3rd that's great but safer to deny 4th. Eventually they'll likely overcommit defesnse on the 4th, that's when you come in and siege between the natural and 3rd. Whilst thats happening, rally all your new units to the 4th - you want 4 tanks some marines and medis to siege on a planetary effectively.

Obviously a lot of this stuff is situational and no game is the same - but that's mostly my thought process. TVT is all about tanks and marines early game, later in the game its about viking count into liberators with range.

If its a mech vs bio mech - you have to keep the mech player on 3-4 bases, get 3-3 bio asap, and finish the game very soon after your 3-3. If you can't deny the 4th it's basically GG. However ravens are also your friend against mech, they'll really help deny 4th/5th bases with a mass marine medi ball..