1 there is no way to get rid of spam as spam is subjective.

2 Yes they were, that's why OP_RETUEN was introduced. It was to fix this problem of small unspendable UTXOs

3 There is no way to prevent miners from directing mining whatever transaction they want if its in concensous. To make spam non concensous see point 1.

4 the jpegs people are worried about are massive in size compared to a legitimate transaction to move coins or make anchors in OP_RETURN. They will be the first thing priced out in a high fee environment. I'm not worried about not being able to move coins because fee is too high. What's the highest been? $50 or so? That's a lot but it's nothing when mainnwt should be the use case of base layer money. No, you can't buy your coffee in that fee environment. But I would argue we should be using L2s as a way to scale throughput and privacy alike. There is plenty of opportunity to move a portion of your stack to Liquid or lightning right now if this concerns you. We can also work on funding more L2s and scaling solutions like eCash and Ark. You need to be prepared for the Layer 1 of money to cost a lot. In the end, unless something big changes (a scary thought, another fork war) that's how it's going to be. And I appreciate that it will be very hard to make that change. That's why I use Bitcoin. Changing concensous is not like changing policy. It's nearly impossible unless you prove beyond shadow of a doubt, that change won't break the worlds money. It's been working since 2009 with exception to the one inflatition bug in 2010, the 6 hours or so it split between .6 and .7 upgrade