Cast Iron drain pipe is failing, how effed am I?

Going to get some bids on replacement/lining and was interested in your opinion on the subject. Live in the Pacific NW, 1960's mid mod with 1.5 baths and a Kitchen all along the back wall of the house.

How do I fix this leaky shower faucet?

Shower drain

I have one of these in my shower and bathroom sink. You click it to plug the tub and when you want it to drain, you press it again and it pops up. The one in my shower is currently busted and is stuck in the "down" position. I unscrewed the metal top and removed the black plastic piece so it will drain (I only have 1 shower). Is this something that I could replace or should I call a plumber? I am a first time homeowner and somewhat handy, but don't want to really mess up my shower.

Old radiator bleed valve

Hi all, looking for some advice if you're able to help. I bleed my rads about once a year but there is a radiator I've got that I've not been able to find the bleed valve....until now. I saw people saying that it might be on the top at the back so I ran my hand along the back and sure enough I found it. I've tried using my radiator key on it but it doesn't fit on. This valve seems to be circular whereas my radiator bleed key is the more conventional squared off slot. Am I going mad or is this valve circular and if so is there a word for the key I'm supposed to use because thus far I've not been able to find it online. Thanks

The Loopty-Loo

I couldn’t believe my eyes.

How to stop this leak

Recently found a pool of water under my sink at traced it back to this water purifier filter thing that is unused. The other end connects to the water valve and looks like more of a pain to deal with than this end. I was thinking of just clamping the plastic hose maybe.

Remove Faucet Handles

Anyone know how to remove these Allen + Roth faucet handles for cleaning/replacement? User manual says to remove them, but does not state how. I’m stumped.

Thanks in advance

Anyone know what catridge this shower system uses?

Maintenance?

Howdy, I have a saniplus toilet, not sure how old, was installed in the basement before purchasing the house. I was just wondering if there's any kind of maintenance that needs to be done or if it's just a flush till it don't flush no more?

Is this black corrosion causing my gas valve to stick?

Leaking hydrant

I've found it dribbling on and off all summer. It has started gushing around the main shaft too. It's only a few feet from the meter and shutoff. Do I take pipe wrenches and spin the head off or dig up the entire hydrant? What's the procedure? There is no identifying maker. Do they make a universal hydrant rebuild with new o-rings etc.?