Technically there is no Hi syllable in Japanese either. There is ひ, which phonologically is neither "Hi" nor "Fi", but somewhere in between. The exact pronunciation varies depending on surrounding sounds, as well as the speaker's regional accent.
So I wouldn't say they really use WiHi. They write WiFi and they say "ワイハイ" which is the closest you can get to WiFi using Japanese sounds. It will kinda sound like WiHi to an English speaker.
To some extent, yes. However the amount of steering you can do this way is rather limited, since a vote only indicates a preference of one candidate over the other.
For example, if you decide to vote Republican out of protest, Democrats might conclude that you like republican policies, and to win your vote back, they need to move even further right. If you decide to stay home and not vote, you don't really give any information to democrats what they actually need to do. They may decide that you are an unlikely voter in any case, and focus towards those folks most likely to turn out (that's generally older white conservative folks).
One option is to vote for some leftist third party. This sends a pretty clear message about what policies you like. The problem is that, apart from the messaging, your vote is almost certainly wasted. You are in effect helping your enemy win in the short term.
The other option is to engage politically outside of just voting. Most people have been convinced by establishment politicians that your only influence is your vote. This is not true. Protests, activism, grassroots movements, local politics are all effective ways to steer your preferred party in your preferred direction. This does require substantially more effort.