I go to Ranger Lakes several times a year, one of my favourite places to go. I'll try to address some of your questions.
Reservations. You're going to need them for the weekends. It's very popular. There's also North Michigan and Bockman CGs that are further down CO 14 toward Walden. Bockman rarely fills up, but it also has no amenities to speak of. Caters to the horsey crowd, there's corrals for horses there.
View. Limited. Looking back toward Cameron Pass (E-SEish) there's some views of Naghu Crags that are quite stunning, and can make for a good photo op. Looking most other directions, no so much. However, there are hiking trails galore in the area, of varying difficulty. There's also a trail from the CG to the Visitor's Center which is not too far west of Ranger Lakes, and is worth a stop to find out what's in the area. Rangers are also very knowledgeable and friendly.
Host. Great guy, he's been the host here for 7 years, comes back every spring from Texas. Firewood available from him.
Electric. It's 30amp. Never had a problem with it.
Water. Yup, you can fill up there. At the entrance to the actual CG loop, there's a small pump building with a water connection. It's a back in location, and even then, you'll need a goodly length of hose. I carry 100 feet of hose, just for this reason. Never had a problem filling up my water tank.
Dump station. It's about 7 miles west toward Walden, at part of the park facilities that house storage and maintainance equipment. It's also at the entrance road for Michigan/Bockman CG as well as North Park Campground, a former KOA that's seen much better times in the past. The dump station fee is included in your fee for Ranger Lakes. There may or may not be accessible water to run through your tanks, it's been spotty in the past.
You're probably aware, but I'll bring it up for anyone else who may not know, you have to pay the campground fee, in addition to the State Parks Pass fee, which is mentioned on their website.
Camping in Fort Collins. There's a KOA at the intersection of CO 14 and US 287 as you come out of Poudre Canyon. There's also Lakeside KOA off North Taft Hill Rd and CR 54G, right off the US 287 bypass around Laporte. As previously mentioned, there's Horsetooth Reservoir and the South Bay CG; it is very popular and fills quickly. Easy access to Horsetooth Mountain Park.
Camping in Loveland area. Also as mentioned, Carter Lake west of Berthoud, 2 CG there -- Carter Lake and Eagle at Carter Lake. These, like South Bay CG, are run by Larimer County. There's also Carter Valley CG off US 34 close to the entrance to the Big Thompson Canyon. It's a commercial CG. Boyd Lake State Park has already been mentioned, is also very popular and reservations will be needed, not just for weekends. It's already been full (the loop that is open all year) several weeks now, is less than a mile from where I live. Commercial CG/RV Parks in the area, for the most part, are very tired, and full of year round residents. Of these, Riverview CG and Resort west of Loveland is the best, not as many long term residents there.
Hope this addresses some of your questions and concerns, and also hope you have an enjoyable stay in this area!
ETA: About Boyd Lake. When it was first established, it was out in the boonies outside of Loveland. Now, there's a lot of development, some of it quite pricy, around Boyd Lake. In the past, you could look east and see farming fields..now you see McMansions. City of Loveland has annexed just about everything around the State Park, and development continues. In spite of that, Boyd Lake has kept a lot of it's appeal, being on the water and with a nice swim beach, access to the Loveland bike/walking trail system, which nearly circles the city now. Still a lot of appeal to Boyd.
