I tie & use a lot of streamer flies, primarily for bass & tidalwater species, but have used them for trout as well. Last trout I caught was on a tiny Clouser Minnow with pink bead chain eyes ( Arctic Fox fur & Polar Flash on a size 8 hook) that I had actually tied with Crappies & other panfish in mind. I generally add some weight to most streamers, but not always. As has been said, both weighted & unweighted can be useful for varying depths & currents. The trick if you wish to call it that, is to cast in such a manner to allow the fly to get to the desired depth. In moving water that often means well up & across so the fly moves down stream to where you want the fly to end up, which should be close to where the fish should be.
In still water or lesser current, your cast may be near where the fish should be or even well past to allow a retrieve that will place the fly in the strike zone.
These others have given you excellent advice. It's been my experience that the species being targeted really doesn't matter when fishing streamers. Most streamers will mimic smaller fish, and big fish eat little fish. However, they can also imitate other things, such as leches or crayfish. There's really no limit to what a streamer might imitate as prey that will be found under water.
IMO, you're rod may be a bit on the lighter side, but doesn't mean can't be effective provided you stay within the limits of the rod. I've cast small streamers on a 3 & a 4 wt many times.
I can't comment of the Cutthroat leaders as I've never used them. But, I will agree that streamer leaders do not need to be extremely long such as you may use with dry flies. I generally go with about the rod length with floating lines, but will shorten as I go to more heavily weighted flies. With an 8 1/2' to 9' rod my shorter leaders will be 6 1/2' to 7' with a floating line. However, with a full sinking line, regardless of the sink rate, I may go to even shorter leader/tippet combinations , even as short as 3', which is often a single section of line serving as both leader & tippet. I have a couple of sinking lines in various sink rates, and use them in waters with depths of at least 10', or where there is strong & fast currents. (Tidal currents most often for me.) Even in waters of 5', if the current is strong, it's difficult to get a fly deep enough sometimes with the weight in the fly alone. Split shot can be added, but I hate using them & feel I get better control with the sinking lines.
The idea of short leaders with sinking lines is the line gets the fly down, and if the leader is too long, the line will be at the desired depth, but the fly will still be well above that depth, so it's necessary to shorten the leader/tippet combination.
For most trout fishing situations, you should be good with what you have as long as you stay within the limitations of the gear you're using. In other words, don't expect to be casting most 8" streamers, particularly if heavily weighted with that 5 wt.
Please keep us informed of your progress, success & failures. It's a learning process & I've said many times that our failures usually teach us much more than our successes.
Sorry for such a long post, but hope it helps.