I can answer this question with a resounding no, pick what you like but if you go AR/Devices then good luck. I have a (funnily enough) AR/En and I don't have Boost Range. Just enjoy your Flamethrower/Full Auto/Buckshot/M30 Grenade (I prefer the grenade over Buckshot as it doesn't need the positioning and isn't short range, plus the radius is bigger than you'd think) then unleash your ST fury if you missed anything, depending on secondary of course, you may just want to throw more AoE at it too 
I am the Blaster, I have filled the role of Tank, Controller and Defender
Sometimes all at once.
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IMO /Ice is a great complementary secondary with both Chilblain and Ice Patch leveraging Ignite effectively, and it has Build up of course and the best defensive power in blasting, Shiver. Very satisfying range extension is available in cheap Dam/range HOs (for endgame) and Alpha slotting, as well as in several IO sets. Keep in mind the base range for Full-Auto is 80ft, as is the underrated M30-Granade, which is usually plenty long for most situations.
I have both a 50 ar dev and a 50 arch em. Both are at range defense cap.
For whatever reason I notice my ar device which clearly has more tools with caltrops, smoke, trip mine, bean bag and taser to evade getting hit still talking a beating much more then compared to my arch em. I believe it comes from being able to use boost range so much that I am out of my enemies range. I also thing but not sure, but maybe archery might have a longer range compared to AR, so I am getting hits back on me much sooner with my ar compared to my archery toon.
I do know that using boost range really helps out because it allows me several attacks and then requires the enemy to run on me. Which further allows me to get off several more attacks .. Also I think since exploding arrow ( I think that is the aoe attack ) has such a quick recharge that it allows me a 2nd shot at any incoming enemies.
1. Why Soft Cap is Important : http://dechskaison.blogspot.com/2011...important.html
2. Limits: http://paragonwiki.com/wiki/Limits
3. Attack Mechanics: http://wiki.cohtitan.com/wiki/Attack_Mechanics
4. Rule of Five: http://wiki.cohtitan.com/wiki/Rule_o...e_Law_of_Fives
Just pair whatever you want. I like the stacking stun ability with AR/EM, but you can live without it, or Boost Range. I'd say Elec or EM is nice for AR because they can supplement your ST damage, since you already have great AOE capability.
Guide: Tanking, Wall of Fire Style (Updated for I19!), and the Four Rules of Tanking
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Synopsis: Explore the fine line between justice and vengeance as you help a hero of Talos Island bring his friend's murderer to justice.
Grey Pilgrim: Fire/Fire Tanker (50), Victory
/EM is one of the best pairings for AR, with BU + Boost Range alongside the stuns to stack with beanbag and hard-hitting smashing/energy attacks for the baddies that shrug off lethal damage like robots (which also get BONUS smashing damage). It's straight-forward, it hits hard, and it works.
On the other hand, /EM trades its immobilize for a knockback punch, meaning it has no ability to leverage Ignite. Ice would have significant survival perks in Ice Patch, Shiver, and Chilblain, and lets you easily leverage Ignite for great ST (or very tight AoE) damage. Different sets allow different tools and approaches to combat, and the best one to use will likely depend on the situation.
Rule number six of an empathy defender is NEVER underestimate a blaster's ability to die. I don't care if he has CM, Fort, both RAs, bubbles (both FF and Sonic), and is fighting next to a Storm defender with hurricane on. If there is a way to die in that situation, the blaster will find it.
I've got a blaster in the works (I've never managed to get one very high into the levels), and he's definitely going to be an Assault Rifle guy. But I'm having a bit of trouble with the secondaries. I understand that AR's niche is AoE damage, particularly with Full Auto available every spawn (and Flamethrower/Buckshot after that's finished), which means I'd want to maximize AoE damage for my character.
/Energy offers Boost Range, which would lengthen the cone and widen the area of effect for the narrow cone of Full Auto, but there's another secondary that would be somewhat more thematic with the character. Would I be gimping myself in picking something other than /Energy, doomed to always miss a portion of every spawn because of that 20 degree cone? Or is 20 degrees wide enough when you're 80 feet away, and I won't have to worry about it so long as my positioning is good?
Thanks for your time.