If you work for an employer that will toss money at you to take educational classes and obtain certs then go for it, but as other's have already stated alot of them have no benefit, certainly the tactical classes unless you're in a TEMS team role. Even so most of the EMS provider's on TEMS teams have a very limited function on said teams, and MOST, not all, are in a warm/cold zone just awaiting for something to go down. There are some very progressive teams which arm the TEMS provider and they function in a stack, but those are very few and far between. Classes and certs are great, but there is no substitute for real world experience. I know plenty of people who have taken a few classes and have some tactical cert who think they're Chris Kyle (both EMS provider's and LEO's) or tactical timmy yet can't shoot for s*it on a practical shooting course. In those roles you're expected to be a gun fighter first and bandaid man second. Not exactly the thought process of most EMS provider's.
As far as the critical care certifications. I don't carry any cert that isn't required by my service to maintain my job, mainly because I have to pay to maintain them and we already have alot that is required. I maintain my FP-C, but have since let my CCEMT-P and PNCCT drop. If it's a class and is enhancing your knowledge great (which CCEMT-P and PNCCT are, and I would encourage people to take these classes first over the FP-C or CCP-C exams). Otherwise the certification is just a way to show a certain level of knowledge and experience and at some point they become redundant. I always laugh when I go to conferences and people have FP-C, CCP-C, EMT-T, RN, BSN, MSN, CFRN, CEN, CCRN etc and give one of the worst lectures or are awful at public speaking. All the credentials in the world doesn't back up a lack of experience, and in my opinion I don't need a ton of alphabet following my name, which I likely am paying to maintain, to prove I know XYZ. I believe your resume, experience, and care you provide should demonstrate those things already. Experienced people can also tell who is the real deal vs. who is a good test taker.