I suppose it all depends on how you look at things. . . lol.
My thinking is that the best, if not always the easiest, solution is to correct the issue at it's root. The lowest-tech, and cheapest(!) way to solve nearly every aquarium dilemma I've ever come across on this forum is to up the level of care given. Sticking to a basic routine of proper maintenance is the only way to truly solve any of these issues that I know of. . .
All of these things that you have listed above are the symptoms of a system that is out of balance. It is not, in my way of thinking, ever a good idea to add an animal to a tank that is in poor condition. Apart from being poor husbandry, treating the symptom with an 'easy fix,' without addressing and finding the proper solution to its underlying cause, will only mask the true problem - ultimately leading to a much higher probability for future issues to arise - though visually, the tank may appear to be 'fine,' at least for a time.
If not cleaning the glass leads to green spot algae, than spend a few moments once a week to wipe the glass when you do a water change!
If algae issues have you down, try limiting the amount of lighting that the tank receives, and ensure that the water is kept clean, limiting the amount of nitrate and phosphates in the tank. If the tank is planted, ensure that the lighting and fertilization is maintained at appropriate levels for the plants kept.
Green water can usually be cleared up by limiting the lighting, and upping water changes to ensure the phosphate levels are in check, though a black out period may be necessary if it has gotten a strong foothold in the tank
Cyanobacteria can be tricky, but typically a combination of manual removal, upping water changes and siphoning to ensure that organic wastes are removed, along with excess nitrates and phosphates, and limiting lighting is enough to take care of it. Ensure the tank is getting adequate water circulation.
Though it is a much-debated subject, plants do not make up for a lack of water changes. Though plants do much to aid in the water quality by removing toxins from the tank, only water changes can remove the solid waste, and keep nitrates and other toxins from accumulating in a closed system.
I'll go ahead and add another very common one that we see often around here:
Snail issues do not require the purchase of a clown loach, which will likely grow too large for most tanks. Instead, try increasing water changes, being sure to siphon detritus and uneaten food from the substrate, and limit feeding. Add some lettuce to the tank at night, and remove it a few hours after lights-out - along with the snails feasting on it. This process may have to be repeated several times, but it will take care of an over-abundance of snails with a bit of time and care on the part of the aquarist!
There are many kinds of things that can be encountered in a tank that can be solved in a variety of ways. . . but if a tank's problems are rooted in the bad habits and practices of its keeper - these can be managed quite simply by the keeper fixing said practices and turning them into good habits to begin with!