First, offer a free multiplatform upgrade for console users, so if they like the game, thay can play on PC not waiting for bug fixes. It's better than just refund policy.
Second, expanded edition would be welcome. It worked for Witcher 1, it could work and save CDPR reputation now.
Third, mechanics and story.
Most important thing is adding a faction standing. Player should have ability to side with Nomads, city gangs or corpos, as he wishes. Attacking gang members should make them hostile and exclude possibility of taking missions from them.
Lifepath exclusive side missions.
Smooth talk ability should be added to intelligence attribute and enhance dialogue and quest options.
Do not tunnel player into friendship with Jackie Welles. Just allow players to play it. Or allow them to not get involved. Fast forward cinematic is awful storywise.
Option of unlocking more optimistic ending - one in which V survives, making the same post-ending exploration possible.
More and mutually exclusive romance options. Player should be forced to make choice between Panam and Rogue earlier in the game, before engaging in one story line.
As for now, Rogue isn't that much attractive romance option to make choice meaningful.
Romance options could be stat-dependant on intelligence, coolness, tech or strength.
Nice addition could be an option to one-night-stand with Evelyn Parker, or making Judy Alvarez bisexual, but it's secondary.
Police - if you can't do anything more intelligent, just script arrival of cars and avs instead popping them out of nothing.
If V become a criminal, all police should be hostile, until he pays for removing bounty, makes plastic surgery or uses something like anonymizer chip.
During hacking, time should be counted down from the very begging, i mean opening hacking screen, not choosing first number.
Add minigames - card games, slot machine games. Beside it will be fun, they could be a source of additional money, while decreasing a need and benefits from grinding a tons of useless guns.