Hey there!
Regarding your first question, there is an interesting piece of research dating from 2004 that addresses the issue relatively well.
I will post a portion of the results that briefly touches on the increase in the various diseases typically associated with smoking. I highly recommend reading the entire paper though in order to understand the methodology used for selecting subjects and gathering the data. The paper also does a good job of summarizing historical pipe specific research (or lack thereof). This study is a nice one because it focuses only on subjects that exclusively smoke a pipe, and separates them based on number of bowls per day, smoking duration, inhalation/non-inhalation (I know I know, you are not supposed to inhale, but some pipe smokers do and they wanted to control for this in their research, which is a good thing), and also previous pipe smokers. The study is longitudinal taking place over 18 years, and they controlled for factors like alcohol consumption, obesity, and previous/current disease. They also include data from a cohort of never smokers to provide a baseline (I was surprised by the number of people who get lung cancer who are never smokers, interesting!) They also look not only at lung cancer/cancer in general, but also heart disease, stroke, and COPD.
Remember though, while this study does control for some environmental/lifestyle risks, it can not control for everything. Things like genetics, diet, stress levels, etc are incredibly difficult to control for in epidemiological studies.
(from the abstract. Baseline is a value of 1.0)
Trends in multivariable-adjusted relative risks associated with current pipe smoking were evident in relation to the number of pipes smoked per day, duration of pipe smoking, and depth of inhalation (Table 3,3A). The relative risk for death from lung cancer increased from 1.99 for men who smoked 1–3 pipes daily to 7.67 for men who smoked 11 or more pipes daily (Ptrend<.001). Similar increases in lung cancer mortality risk were seen with the duration of smoking (Ptrend = .003) and with depth of inhalation (Ptrend<.001). Statistically significant increasing dose response trends were observed with years of smoking for coronary heart disease, chronic obstructive pulmonary disease, and stomach and bladder cancers and with depth of inhalation for coronary heart disease, chronic obstructive pulmonary disease, and pancreas cancer. We observed an anomalous inverse association with depth of inhalation for cerebrovascular disease that we cannot explain.
Here is the link
Association Between Exclusive Pipe Smoking and Mortality From Cancer and Other Diseases - https://academic.oup.com/jnci/article/96/11/853/2520796
It is an interesting read! The takeaway is pretty common sense in the end, being that the more you smoke both in volume and time, the higher the risk for disease.