Most good faucet repair will recommend replacing a gate valve regardless of its condition. The time to discover if it will work is not during a flood in your bathroom. If you have it replaced with a ball valve then check your water heater and laundry valves, too. Have them replaced at the same time with premium ball valves. Ball valve laundry bibbs make it easy to shut off the water to the washer after each use which may help to prevent floods in the future.
There are two, one on each side of the toilet, closet bolts which hold the toilet to the floor. If there are caps over the bolts, remove or pop them open. Using a small crescent wrench unscrew the nuts from the bolts. Alternate side to side when unscrewing this will be much more important when reinstalling the water line repair bolts but alternate anyhow.
This so impressed me, that I thought, here is the man who might fix my sink problem, and I told him about my kitchen sink. The look on his face was priceless, as he said, "Ridiculous! Sinks don't leak if they're new." He even showed me what to do. He took out a big heavy-duty screwdriver with a big flat-head blade and showed me. "This is what's probably lose." He put the blade of the screwdriver in a notch the size of a giant screw head that was right in the center of the drain basket where the plug sat in.
OR, you can think about developing a group, where relationships prevail, your time and efforts come with great rewards, and you can multiply your efforts through helping others succeed, as they help you with introductions and referrals. So with much less time and effort, you can benefit from creating your own referral group.
As with anything, when you are not sure how to fix a plumbing issue and when you don't have the proper equipment, you should contact a professional. They can usually find out what the problem is and resolve it for you in a short period of time. They will also be able to tell you if you have any other problems and water line repair they can suggest resolutions.
And the way to know what's sufficient? Well, until the work is done an the bill paid you won't know for certain, but this is the best that can be suggested and normally works very well.
Water leak detectors can keep your home safe. They can give you the peace of mind knowing that you won't come home to a house full of water. It is a lot less expensive to buy a water detector than it is to pay thousands of dollars in home repair costs.