Yes, you can buy one EURUSD lot with 100K balance in your account and you have 1:1 leverage. People are confused about it. You can buy one E-mini in an account with balance equal to face value and you will be 1:1 leveraged. See this expert article for details.
Yes. If your account is big enough to allow you to buy a futures contract for the nominal price. Example an ES contract is 50 x 2000 = $100,000 In forex one can do cash exchange from account base currency to an other currency. That mean you go long that currency and short your base currency.
That is not accurate. While futures are inherently leveraged products foreign exchange/fx/currencies are certainly not. Most do trade currencies on a leveraged basis but that is not a requirement. You can open a non margin account and trade currencies. Or you can trade currencies in a margin account up to the size of your account balance.
Sure,why not ? You can even adopt an unleveraged buy and hold portfolio through futures - it might be better than holding the underlying depending on the way you are taxed - for instance if you suffer high witholding tax on dividends but not tax on cap gains, ES sound like a good alternative to Spy. I regulary do unleveraged forex trades but they are more about rebalancing currency exposure, seeing how the USD moved since last year there was still money to be made unleveraged.
It seemed you really know your things, trading with leverage is a suicide to account but unfortunately a lot of people (include those super smart one) fall into this trap, as they don't realize they are playing with the noise than signal. Their brokers (and the brokers' affiliate) and bucket shop owners are more than happy to let them to continue this and racking up all the commissions/slippage. You can trade forex without leverage. For future, just go for those ETF such as SPY, QQQ and etc.
yes, but almost nobody can make money trading without leverage. Leverage allows small traders to profit from small moves. Without leverage you need long sustained moves to make any kind of significant money. That is why I almost never trade and only buy and hold in my cash account. But in spot or futures I suddenly have 40 times more money, and a small move for the world can be a very big move for me a small trader.
You can deleverage your position by using options buywrites with lower total delta exposure. In addition, you can maintain higher cash balances to effectively produce a de-levered exposure. Example. Buy ES - Sell 1 ATM Call (50 delta) Exposure wise is 100,000 -50,000 = 50,000 net delta dollars Maintain a 50,000 balance and you have ALMOST 1:1 exposure between the value of your account and the value of your exposure. The higher the market goes, the less excess capital you need to maintain in your account. Warning: This is highly simplistic. You will have increased your exposure to changes in volatility. And, there is forward curve and basis effects you may want to worry about compared to just buying SPY.