Regarding the estate tax, I would say that the issue is a bit more nuanced than a simple tax or no tax.
IMHO, the "Estate" should include the deceased and any nuclear family components, therefore (unless otherwise laid out in the will), moneys that go to spouse and/or children should be treated as if they were going to the deceased before he/she died. Much like liquidating an LLC, any "gains" should be taxed at the applicable capital gains rate, but money that already has been taxed should be left alone.
Same with giving your spouse a gift. IIRC, the IRS stipulates that a one-time gift up to a certain amount is not considered "income," but outside of that, any money or gifts above a certain value are considered taxable income. This is classic government overreach and over-taxation, and flies directly in the face of the "community property" definitions as applied to divorce settlements ("What's mine is yours...").
Regarding tariffs, as with the IRS and taxes, I'm certainly no expert, but I find the whole debate interesting.
Economists have a tendency to crunch numbers without taking into account variables - for example, cutting taxes results in "X" amount of lost revenue compared to "Y" amount of spending, resulting in a net financial impact.
Historically, however, administrations that cut taxes often triggered increased government revenue due to an expanding tax base (diminished tax burdens resulting in increased job growth and increased individual spending - ergo, increased number of people paying taxes and increased gains from sales taxes). Calculating lost revenue strictly by Xs and Os can be misleading. The Kennedy and Reagan administrations both cut income taxes, and tax revenues went up, not down. The problem is that our elected officials can't resist the temptation to concomitantly increase spending as well...
Yes, certainly in the short term, it would appear that tariffs would have a significant negative impact on consumer prices, essentially acting as a "tax." However, what if a short-term pain turns into a long-term gain? Both China and Mexico have a lot to lose if they play hardball and don't acquiesce. If tariffs force countries to stop currency manipulation, techo theft, undercutting prices by utilizing slave labor, etc., the end result of leveraging those tariffs could very well pay off big in the future, especially for an American labor force that isn't given a level playing field.
Also, we need to keep in mind that many of the goods (not all certainly) can be obtained at least temporarily from other countries with fairer trade practices, i.e., Taiwan, Korea, The Netherlands, Singapore and the Norwegian countries. Ramping up trade agreements with other countries, while working on regaining energy independence would put tremendous pressure on our current trade partners, China in particular.