My dad has spells where he has vertigo lips tingle and has a weird chemically taste in his mouth, could this be signs of stroke?

Absolutely. And he should be seen. Also, rule out a focal epilepsy variant.
Possibly. Signs of stroke can vary greatly. What you described can potentially represent signs of transient ischemic attacks (or so called "mini strokes"). This requires careful evaluation by a physician. Other conditions can do this as well. Notably, seizures, anxiety attacks and migraines can present this way.