Hi. Yes, any aspect between any two planets can be troublesome, at least initially. A lot depends on what is going on in the rest of the chart of course. Any aspect between Mars and Pluto implies that these planets will work together in one way or another, and this may or may not accord with the needs and values of other parts of the chart. For example, if someone has a very airy chart, then they may find it difficult to use a Mars which is followed around by Pluto. If, like most people on the forum seem to, you have Pluto in Scorpio, and your Mars is in Cancer or Pisces, then this makes this Mars yet more watery. But in the absence of the chart, I must let you assess whether such clash of values of this kind is occurring within you.
Trines suggest an innate understanding of how the planetary functions can work together, but it doesn't necessarily mean that either or both of these functions are operating creatively and consciously. We may find it easy to combine the destructive sides of the functions! A difficulty with trines is the lack of tension generated, because this means that we are less likely to question how we are combining the functions concerned. Hard aspects can be more full-on, but they do bring a sense of self-doubt and internal resistance which can propel the individual to find more satisfying ways to express the two planets together.
It could be that someone in your early life found it all too easy to express the Mars Pluto dynamic in destructive ways - satisfied that it was ok to be like that. If your experience of the Pluto-Mars dynamic in early life was problematic, then you will need to make efforts to turn this around. This will involve avoiding the downside of trines mentioned above.
Once you've assessed the relationship of the Mars-Pluto aspect to the rest of the chart, you can look at how the chart as a whole might be defended against the expression of this aspect, taking into account that your impression of this aspect is probably caged within your memories of a negative role model, and that you may be defended against becoming like this person. Then you can look for ways of expressing Mars Pluto that do not threaten the values of the chart, and also where you might need to relax the defences of the rest of the chart to meet Mars Pluto half-way.
Having shown concern for hijacking the thread, and with a affable manner in general, it would seem that you err on the side of caution when it comes to asserting your needs. But you will express this aspect in some way, perhaps you can be very determined about some things, and perhaps when you have very strong desires for certain things. You may assert yourself strategically rather than directly (having learnt this by having to navigate a wilful person in your early life). But whatever expression it takes, it would be good to acknowledge it fully to help you to further integrate the Mars-Pluto aspect into your sense of self.
Because it is a trine rather than a square or opposition, it may be useful to treat the Mars-Pluto aspect as a single entity at first - perhaps imagining it as a combination of Mars in Scorpio and Mars in whatever sign it is actually in. Get a feel for it as a whole and see how its needs and values differ from those of the rest of the chart.