...unproductive to them team, our team lost cause we had 5 snipers redline sniping. And not coming out to defend the objective.

The changes are really good but it has not changed the fact that snipers still snipe from the redline in a carefree fashion. I thought the change will bring them out from the redline but that is not the case. Actually its has become more tough to counter-snipe them, cause you have to do so in from the middle of the battlefield.

I demand the sniper rifle damage be halved and headshot multiplier negated when in the redline. Actually this should apply to redline railgun tanks as well (not as prominent as before but can still be found).

Exactly, how do you balance between a red line camper and a team getting stomped into the red line. Seriously, I've been killed straight from the MCC drop. Should my shots be penalized because of that? Kind of sounds like Warbarge logic- 'you're already beating the snot out of the other team, let's kick them again, and by the way here's some salt to pour in there'.

How about a countdown timer to shot damage diminishment. Similar to the opposite red line, give 20 seconds to move out or your damage drops by 5%/second giving an additional 20 seconds to cross over. If you're truly trapped in your red line, you're probably dead in about that amount of time anyways. Trust me, I've been stomped back on more than a few occasions, lol. Getting killed at your 'safe' spawn point sucks, lol

Or... one could simply retune the Redline instead of removing it in entirety...
First by extending the area of all prior Redline areas back a ways, and then designating it with an orange border to differentiate the regions.

However, if you travel into the enemy orange line the further you go the LESS your maximum armor and shield become, and if you exit the orange, they restore to normal.

If you've ever played Runescape and tried the "Wilderness" before you'd know how these advancing regions work, but instead of going up a wilderness level, the affected party looses max HP relative to the tier they enter... so..
Outside of orange 100% all stats,
Area 1 --90% shield and armor (largest region mainly for deployment)
Area 2 (within handheld range of spawn) -50% shield and armor and -10% weapon damage
Area 3 (inside spawn proximity regions) -80% shield and armor and - 30% weapon damage

Defenses would be indestructible very-short-range manual turret systems that can target things within the orange region only, but loose power if the target is in a lower ranked region.

This way the complainers could run into the orange line to deal with troops/tanks they feel to be problematic. Would probably promote heavily dampened scouts.

Example,
If I had 100 shield and 100 armor, and ran into area 3, I would be left with 20 shield and 20 armor, and would not be able to heal over that until I left into area 2, then I would be able to heal back up to 50/50... and upon leaving all zones would be back to 100/100 maximum possible healing.
Zone auras are unable to kill players.