I think you are both right and wrong. What you say about conservatives we elect, or that are appointed to the bench, is true - they are rarely trustworthy. And even the very best are going to have areas where they are awful. For example, both Rand Paul and his father Ron Paul are stanch libertarians EXCEPT if you are talking about abortion, and perhaps gay marriage.
But with the Tea Party, it isn't, by nature, as coherent, or defined a position as say the Social Conservatives, and it isn't an organization, like say the Republican Party. It is a strong movement among voters, not the professional observers, nor the politicians.
It is the description of those American citizens who decided to become active in favor of reducing government size, reducing government taxation, spending, regulation, debt and to increase the adherence to the constitution. I believe you will find nearly total agreement between those who would say they idenitfy with the Tea Party and those positions. And, strangely enough, there are many who agree with each of the principles, but adamantly deny that they are part of the Tea Party. This is a party that doesn't require joining, or registering. It is just a coorespondence with those beliefs and a determination to vote that way, and an emotional sense of taking the country back from politicians.
Now, there is great divergence on how far these things should go (just to the budget when Clinton was president or all the way to a minarchy?), but even if they currently have different stopping points, they are all going the right direction. There is also a significant minority of the Tea Party that are strongly in favor of social conservative issues (like prayer in public places, gay marriage, etc.) and this is a battle that will go on for a while, till the conservative wing of the Republican party is not just the majority of that party, but has become mostly libertarian (in a decade or so)
I would look at the tea party as nothing more (or less) than a grass roots awakening to the degree of statism we have acquired, and the dangers, and a determination to fix this at the voting booth. Their education in recent years has been considerable, but in terms of where it needs to be, it is still early times. Also, whether this or that part of the tea party is motivated by altruism or religion is not the key issue now. As we move forward they need to get a stronger and stonger awareness and better education - on key political principles and key economic principles. Eventually, they need to shift from altruism to rational self-interest... There is no such thing as too soon, but in terms of when it is critical.... that is down the road aways. Liberals, progressives, moderates, the establishment are all trying to define the tea party as kooks, as racists, as neanderthal right-wing, or some other undesireable group - but they are best understood as just all people who have reached a strong commitment to vote out all big government people and get a smaller government that is fiscally responsible (which is exactly NOT how proponents of big government want anyone to see them).
The Tea Party is the first step. No matter what you call it, the first step has to be voters unifed enough to take back control from the progressives - without them we are not going to get progressives out of power, we aren't going to effect good change. With the Progressives removed, the second step is to raise the level of understanding of the voters to much higher levels on political principles and on economic principles so that they continue to move in the right direction (this is hard, because many will see the job done in the first round and go complacent again), after that we need to change the educational system and the media should change in response to market pressures with this change in the voters and the passage of time.
All and all, we have a wait of several generations to see the system not just changed, but on a sound basis and with voters, officials, the educational system, media, all of whom understand better what it needs to be and can protect all gains in that direction. And this is seeing the current growing trend in an optomistic light. The progressives will take each loss, when they occur as an excuse to double down, and their willingness to lie and obscure their agendas give them big advantages, particulary in a crisis.