Gravity could use being nice to, part of Titan's cost is 50hp, this equipment deserves to be a bit cheaper since it's a bit awkward (cheaper is faster, this is slow due to having to wait to use active, so compensation)
Honestly shield should cost 3. Shields generally get a -2 cost improvement when upgraded, so I think Titanium shield would cost 2 if upped if it didn't gain DR (See Tower Shield)
View this as a long sword that can become a tower shield
Shield's ability should cost less than Sword's so that it's generally cheaper to run upped (ie shield-deck's play shield, use ability, play 2nd shield is cheaper than sword-deck's play sword use ability, play 2nd sword)