Crafting Question

I have a finished craft shield. Now is it possible to switch crafting guilds without penalty?
I wanna unlock the ki and gear from other crafts now but dont dare switch guilds incase i "loose" my shield.

You cannot possibly lose the shield without throwing it away and zoning.

I haven't personally verified going above 70 in subcrafts with a shield, but I am nearly 100% certain you will be allowed to do whatever you want (except make a new shield) without any issues.

There's no risk, try whatever you want. They can't take your shield, you have to give it up manually through a very explicit and thorough process