Well, there are definitely preferred EV spreads for different roles.
Fast Physical sweepers will usually run 252 Attack and 252 Speed with Jolly, the only real exceptions being Swift Swim/Sand Rush/Slush Rush/Chlorophyll and/or a Choice Scarf (where you would run Adamant).
Fast Special sweepers will go for 252 Special Attack and 252 Speed with Timid, the exceptions being the same as above (but Modest instead of Timid).
Special walls will use 252 HP and 252 Special Defense with Careful/Calm, unless it is just a natural special wall (take Blissey and Chansey for example, they have massive Special Defense, but they usually run 252 HP/252 Defense/4 Special Defense).
Physical walls will have about the same guidelines as Special Walls, just with 252 Defense and Bold/Impish.
To answer your specific question, phasers can run any type of EV spread, usually with 252 HP since phasing moves have negative priority.
Clerics tend to run 252 HP, with the rest of the EVs split into its defenses. Bold/Calm are usually the preferred natures, but Careful/Impish could work (though I can't think of a physical cleric off the top of my head).
Spinners are interesting. Some of them are speedy offensive Pokemon (like Excadrill) and some are more defensive (such as Coalossol). So, this is an interesting role. Excadrill commonly runs Rapid Spin though, and Excadrill most commonly has 252 Attack, 4 Special Defense, and 252 Speed with Jolly.
You asked about spinblockers, though "spinblocker" is a term assigned to Pokemon immune to Rapid Spin, aka Ghost types.
For a tank, it depends on the Pokemon. Some Pokemon run 252 HP and 252 Special Attack/Attack as a tank, but sets can very greatly. For example, I use 252 HP, 112 Defense, 140 Special Attack, and 4 Special Defense on a tank Clefable.
Hope this helps! :)
(If you want more roles, I'll add more)
