Laser rifles are much more effective than assault rifles, and quite affordable. Laser rifles will reliably one-shot both Sectoids and Thin Men, which isn’t true of assault rifles, and lasers are accurate at much longer ranges. Honestly, lasers are a much higher priority than body armor, because equipping your squad with lasers really early means you can reduce enemy return fire substantially.
I had no difficulty doing it. 1 plasma rifle costs as much as 4 laser rifles, or 6 if you factor in the the value of selling Elerium and Alloys. You’re trading at most one plasma rifle for equipping your entire squad with lasers.
I agree, SHIVs are definitely questionable through most of the game. The issue isn’t so much that they’re expensive, it’s that it’s impractical to build a Foundry and research SHIVs early enough to make them a practical alternative, and SHIVs of course don’t gain experience. If I were to tweak things, I’d make the basic SHIV available at game start, and move the upgrade research (laser weapons, plasma weapons, floaters) to the regular research track.
As I said, careful play can avoid the loss of countries. For example, engineers as mission rewards are important for satellites, since there are limits to how quickly you can expand your engineer population through workshops, and engineers limit the number of uplinks you can support. There’s also the tactic of deliberately letting a country hit 5+ panic because you’re going to launch a satellite over it at the end of the month.
That said, losing a country is largely an emotional issue. Lost countries are a much smaller setback than you might imagine. Short of losing 8 (which loses the game), you’re losing potential income, not present income, and possibly a potential continent bonus, though you can pick easily enough pick missions so that you’ll only lose one such bonus. The aliens don’t get any bonuses for controlling a country.
I personally strove for 100% coverage when I played, but there were people on the official forum who did quite well while largely ignoring losses. There comes a turning point where you’re absolutely swimming in income, so losing even the full 7 you are allowed won’t cripple you financially in the long run.